Audi 01J Multitronic CVT

Variable Automatic

Transmission

multitronic® 01J

Self-Study ProgramCourse Number 951103

Audi of America, Inc.3800 Hamlin RoadAuburn Hills, MI 48326Printed in U.S.A.August 2001

Design and Function

Audi of America, Inc.Service TrainingPrinted in U.S.A.Printed 8/2001Course Number 951103

All rights reserved. All information containedin this manual is based on the latestinformation available at the time of printing andis subject to the copyright and other intellectualproperty rights of Audi of America, Inc., itsaffiliated companies and its licensors.All rights are reserved to make changes at anytime without notice. No part of this documentmay be reproduced, stored in a retrievalsystem, or transmitted in any form or by anymeans, electronic, mechanical, photocopying,recording or otherwise, nor may thesematerials be modified or reposted to other siteswithout the prior expressed written permissionof the publisher.

All requests for permission to copy andredistribute information should be referred toAudi of America, Inc.

Always check Technical Bulletins and theAudi Worldwide Repair Information Systemfor information that may supersede anyinformation included in this booklet.

Trademarks: All brand names and productnames used in this manual are trade names,service marks, trademarks, or registeredtrademarks; and are the property of theirrespective owners.

i

multitronic®

The name multitronic® stands for thenew variable automatic transmissiondeveloped by Audi. It is also commonlyknown as a CVT.

CVT is an acronymfor “Continuously VariableTransmission.”

The CVT concept improved by Audi isbased on the long-established principle ofthe chain drive transmission. According tothis principle, the reduction ratio betweenthe lowest and highest ratios can becontrolled steplessly by means of a Variator.

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Contents

This Self-Study Program provides you with informationconcerning variable automatic transmission featuresand functions.

The Self-Study Program is not a Repair Manual!

When carrying out maintenance and repair work, it isessential to use the latest technical literature.

Important/Note!

New!

Introduction ............................................................................. 1

The Transmission Concept,Specifications

Modules ................................................................................... 7

The Flywheel and Damper Assembly,Sectional View of Transmission,The Forward Clutch/Reverse Clutch withPlanet Gear Set, The Clutch Control,The Clutch Cooling System,The Auxiliary Reduction Gear Step,The Variator, The Transmission Control,The Torque Sensor, The Splash Oil Cover,The Chain, The Oil Supply,Electro-Hydraulic Control,Selector Shaft and Parking Lock,Transmission Housing Ducting andSealing Systems, Hydraulic Circuit Diagram,ATF Cooling

Control ................................................................................... 59

Transmission Control Module J217,Sensors, CAN Information Exchange on multitronic®,Auxiliary Signals/Interface, Functional Diagram,Dynamic Control Program

Service.................................................................................... 91

Towing, Special Tools

Teletest ................................................................................... 95

Audi Variable Automatic Transmission Teletest

iii

1

Introduction

Transmissions are required to matchthe torque characteristics of the engine tothe vehicle.

Usually, multi-step reduction gears areused, such as manual transmissions,automated manual transmissionsand multi-step automatic reduction gears.A multi-step reduction gear alwaysrepresents a compromise betweenhandling dynamics, fuel economy anddriving comfort.

In an engine, torque flow is notintermittent but continuous. A variabletransmission ratio is, therefore, ideal forengine power utilization.

The CVT designs which have been availableon the market until now are based uponthe “chain drive principle.” Because oftheir limited abilities to transfer power,

however, they have only been suitable forsubcompact cars and vehicles in the lowermid-range segment with low engineperformance.

Audi chose the belt/chain drive principlefor the development of its CVT design,because it is the most advanced form oftransmission available today.

Audi’s objective was to develop a CVTdesign for high-performance premiumsegment vehicles that sets new standardsin terms of driving performance and fueleconomy, as well as in handling dynamicsand comfort.

Audi is the first to present a CVTthat can be used in combinationwith 3.0-liter V6 engine with220 bhp (162 kW) and 221 lbs-ft(300 Nm) of torque.

Manual Transmission multitronic® CVTStepped Mode O1V / O1N

P

R

N

D

P

R

N

4

3

2

D

R 1 3 5

2 4

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2

Introduction

The Transmission Concept

Engine torque is transmitted to thetransmission through either a flywheel anddamper assembly or a dual-mass flywheeldepending on engine version.

There is one “wet“ plate clutch for forwardtravel and one for reverse travel; both actas starting clutches.

The rotational direction for reverse ischanged by means of a planetary gear train.

TransmissionControlModule J217

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The engine torque is transmitted to theVariator via an auxiliary reduction gear stepand transferred from there to the final drive.

The electro-hydraulic control, together withthe Transmission Control Module J217,forms a unit which is located in thetransmission housing.

The Tiptronic function provides six“speeds“ for manual gear selection.

Flywheel andDamper Assembly

ReverseGear Clutch

Auxiliary ReductionGear Step

Variatorwith Chain

PlanetaryGear Train

ForwardClutch

HydraulicControlModule

3

Introduction

The key component part of themultitronic® is the Variator. It allowsreduction ratios to be adjusted continuouslybetween the starting torque multiplicationratio and the final torque multiplication ratio.

As a result, a suitable ratio is alwaysavailable. The engine can always operatewithin the optimum speed range regardlessof whether it is optimized for performanceor fuel economy.

The Variator has two tapereddisc pairs — a set of primary pulleys(pulley set 1) and a set of secondary pulleys(pulley set 2) — as well as a special chainwhich runs in the V-shaped gap betweenthe two tapered pulley pairs. The chain actsas a power transmission element.

Pulley set 1 is driven by the enginethrough an auxiliary reduction gear step.Engine torque is transmitted via thechain to pulley set 2 and from here to thefinal drive.

One of the tapered pulleys in each of thesets of pulleys can be shifted on the shaftfor variable adjustment of the chain trackdiameter and transmission ratio.

The two sets of pulleys must be adjustedsimultaneously so that the chain is alwaystaut and the disc contact pressure issufficient for power transmission purposes.

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Set of Primary Pulleys(Pulley Set 1)

Set of Secondary Pulleys(Pulley Set 2)

Downforce

Drive

Wide

Narrow

Variator in Starting Torque Ratio

Variator in Final Torque Ratio

4

Introduction

multitronic® for

Maximum Comfort

In automatic mode, any ratio is possiblewithin the bounds of the TCM.The factors that determine rpm are driverinput (accelerator pedal position andactuation rate) and rolling resistance.Transmission ratios are adjusted completelyfree of jolts without interruption in tractivepower flow.

In the Tiptronic function, there are sixdefined shifting characteristics for manual

gear selection. The driver can thereforechoose handling dynamics to suit his orher personal preferences. This feature isparticularly useful on downhill gradesfor example, as the driver can determinethe engine braking effect by selectivedown-shifting.

Top speed is achieved in 5th gear.The 6th gear is configured as an economygear or overdrive.

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5

Introduction

The Tiptronic can also be operatedfrom the steering wheel as an optionon some vehicles.

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6

Introduction

All the specifications in thisSelf-Study Program referonly to the multitronic® withthe code DZN.

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Specifications

Designation: multitronic®01J

Factory Designation: VL 30

Code: DZN

Maximum Transferable Torque: Maximum 229 lbs-ft (310 Nm)

Range of Ratios of the Variator: 2.40 : 1 to 0.40 : 1

Spread: 6

Ratio of Auxiliary Reduction Gear Step: 51/46 = 1.109 : 1

Final Drive Ratio: 43/9 = 4.778 : 1

Operating Pressure of Oil Pump: Maximum Approximately 870 psi (6 000 kPa)

ATF for multitronic®: G 052 180 A2

Axle Oil for multitronic®: G 052 190 A2

Gear Oil Quantities:ATF New Filling (Including ATF Cooler and ATF Filter) Approximately 7.9 qt (7.5 liters)ATF Change Approximately 4.8 qt (4.5 liters)Axle Oil Approximately 1.4 qt (1.3 liters)

Gross Weight (Without Flywheel): Approximately 194 lbs (88 kg)

Overall Length: Approximately 24 in (610 mm)

7

Modules

Damper

The Flywheel

and Damper Assembly

In reciprocating engines, the unevennessof the combustion sequence inducestorsional vibration in the crankshaft.

This torsional vibration is transmittedto the transmission and results inresonant vibration, producing noise andoverloading components inthe transmission.

The flywheel and damper assemblyand the dual-mass flywheel dampentorsional vibration and ensure theengine runs quietly.

In the 3.0-liter V6 engine, engine torque istransmitted to the transmission through aflywheel and damper assembly.

Because four-cylinder engines do notrun as smoothly as six-cylinder engines,a dual-mass flywheel is used infour-cylinder engines.

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Dual-MassFlywheel

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Flywheel

8

Modules

Sectional View of Transmission

For better representation,the oil pump and the transfercase are shown folded on thecutting plane.

9

Modules

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Housing, Screws, Bolts

Hydraulic Parts/Control

Electronic Transmission Control

Shafts, Gears

Plate Clutches

Pistons, Torque Sensors

Bearings, Washers, Circlips

Plastics, Seals, Rubber

Color Definitions

10

Modules

The Forward Clutch/Reverse

Clutch with Planet Gear Set

In contrast to multi-step automatictransmissions, such as the 01V, which usea torque converter, separate clutches areused for forward and reverse travel in theAudi CVT design. These “wet plateclutches” are also used to executegearshifts in multi-step automatictransmissions. They are used for drivingoff and transmitting the torque to theauxiliary reduction gear step. The drive-offprocess and torque transmission aremonitored electronically and regulatedelectro-hydraulically.

The electro-hydraulically controlled wetplate clutch has the following advantagesover a torque converter:

• Low weight

• Very little installation space is required

• Adaptation of clutch engagementcharacteristic to driving situation

• Adaptation of slip torque todriving situation

• Protective function in the event ofoverloading or misuse

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Reverse Clutch

ForwardClutch

Planet Carrier

Input Pulley Set 1(Auxiliary Reduction Gear Step)

Forward Clutch/Reverse Clutchwith Planetary Gear Train

Planetary GearsTransmissionInput Shaft

Ring Gear

11

Modules

The Planetary Gear Train

The planetary gear train is constructed as aplanet reversing gear set and its onlyfunction is to change the rotational directionof the transmission for backing up.

The reduction ratio in the planetary geartrain is 1:1 when backing up.

Assignment of Components

The sun gear (input) is linked to thetransmission input shaft and the steelplates on the forward clutch.

The planet carrier (output) is linked to thedrive gear, the auxiliary reduction gear step,and the lined plates on the forward clutch.

The ring gear is connected to theplanetary gears and the lined plates on thereverse clutch.

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Steel Plates and Lined Plateson Forward Clutch

Ring GearSteel Plates and Lined Plateson Reverse Clutch

Sun Gear Input Pulley Set 1(Auxiliary ReductionGear Step)

Planet Carrier withPlanetary Gears

TransmissionInput Shaft

12

Modules

Power Flow in the Planetay Gear Train

Torque is transferred to the planetary geartrain via the sun gear which is connected tothe input shaft and drives the planetarygears 1.

Planetary gears 1 drive planetary gears 2,which are in mesh with the ring gear.

Planet Carrier

The planet carrier (output planetary geartrain) is stationary because it acts as theinput for the auxiliary reduction gear stepand the vehicle is still not moving.

The ring gear idles and rotates athalf engine speed in the direction ofengine rotation.

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Direction of Rotation of Components when

Engine is Running and Vehicle is Stationary

Transmission Input Shaftwith Sun Gear

Ring Gear

Planetary Gear 2Planetary Gear 1

13

Modules

Power Flow During Forward Travel

The steel plates on the forward clutch arelinked to the sun gear and the lined platesare linked to the planet carrier.

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When the forward clutch is engaged, itconnects the transmission input shaft tothe planet carrier (output). The planetarygear train is locked and rotates in the samedirection as the engine; the torquetransmission ratio is 1:1.

Oil Pressure for ClutchTorque Flow

Forward Clutch

Planetary Gear Train

14

Modules

Power Flow in Reverse

The lined plates of the reverse clutchare connected to the ring gear and thesteel plates are connected to thetransmission housing.

When the reverse clutch engages, it holdsthe ring gear and thereby prevents thetransmission housing from rotating.

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Reverse Clutch

Torque is then transmitted to the planetcarrier, which begins to rotate in theopposite direction to the engine. Thevehicle moves in reverse.

Road speed is limitedelectronically when thevehicle is in reverse.

The Variator remains in thestarting torque ratio.

Oil Pressure for ClutchTorque Flow

Ring Gear

15

Modules

Accelerator Pedal AngleEngine SpeedNominal Engine SpeedTransmission Input Speed, Pulley Set 1Transmission Output Speed, Pulley Set 2

20

40

60

80

100

1000

01 2 3 4 5 6 7 8 9 10

2000

3000

4000

0

Accelerator Pedal100% Depressed

Eng

ine

Spe

ed

Time in Seconds SSP 228/052

20

40

60

80

100

1000

01 2 3 4 5 6 7 8 9 10

2000

3000

4000

0

Eng

ine

Spe

ed


AcceleratorPedal 60%Depressed

20

40

60

80

100

1000

01 2 3 4 5 6 7 8 9 10

2000

3000

4000

5000

6000

0

Eng

ine

Spe

ed


Accelerator Pedal100% Depressed+ Kickdown

The Clutch Control

Clutch Engagement

Engine speed controls CVT clutchengagement to initiate vehicle motion.

The accelerator pedal angle and applicationspeed set by the driver and the control maprequirements of the Transmission ControlModule J217 determine the clutchengagement characteristics for eachvehicle start from rest.

Depending upon the specific driver inputsfor each start, the Transmission ControlModule J217 sets a nominal engine speedat which clutch engagement will take place.

With the vehicle at rest, moderateapplication of the accelerator pedal(characterized by slow movement to asmall accelerator pedal angle) initiates thetransition from engine idling speed toclutch engagement speed at a relativelylow engine speed. Short clutch slip timesand low engine speed at clutchengagement will provide the best fueleconomy.

For a performance start from rest, heavyapplication of the accelerator pedal (quickmovement to a large accelerator pedalangle) initiates the transition from engineidling speed to clutch engagement enginespeed at a higher engine rpm. The greatertorque developed at higher engine rpmyields faster vehicle acceleration.

Differences in engine type andperformance characteristics also have aneffect on CVT clutch engagementcharacteristics.

16

Modules

Electronic Control

The following parameters are used forclutch control:• Engine speed• Transmission input speed• Accelerator pedal position• Engine torque• Brake applied• Transmission oil temperatureThe Transmission Control Module J217calculates the nominal clutch pressurefrom these parameters and determinesthe control current for Pressure ControlValve -1- for Automatic Transmission N215.The clutch pressure, and thereforethe engine torque to be transmitted by theclutch, changes almost in proportion tothe control current (refer to “HydraulicControl,” page 17).Automatic Transmission Sender -1- forHydraulic Pressure G193 registers theclutch pressure (actual clutch pressure) inthe hydraulic control. Actual clutch pressureis continuously compared to the nominalclutch pressure calculated by theTransmission Control Module J217.The actual pressure and specified pressureare checked continuously for plausibilityand corrective action is taken if these twovalues deviate from one another by morethan a certain amount (refer to “SafetyShut-Off,” page 18).To prevent overheating, the clutch iscooled and clutch temperature is monitoredby the Transmission Control Module J217(for more detailed information, refer to“The Clutch Cooling System,” page 23, and“Overload Protection,” page 18).

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Transmission ControlModule J217

Automatic Transmission Sender-1- for Hydraulic Pressure G193

Pressure Control Valve -1- forAutomatic Transmission N215

17

Modules

Hydraulic Control

Clutch pressure is proportional to enginetorque and is not dependent on thesystem pressure.A constant pressure of approximately73 psi (500 kPa) is applied by the pilotpressure valve to the Pressure ControlValve -1- for Automatic Transmission N215.Pressure Control Valve -1- for AutomaticTransmission N215 produces a controlpressure which controls the position of theclutch control valve depending on thecontrol current calculated by theTransmission Control Module J217.A high control current results in a high

control pressure.

The clutch control valve controls the clutchpressure and therefore also regulates theengine torque to be transmitted.

The clutch control valve is suppliedwith system pressure and produces clutchpressure in accordance with the activationsignal from Pressure Control Valve -1- forAutomatic Transmission N215.A high control pressure results in a high

clutch pressure.

The clutch pressure flows via the safetyvalve to the manual selector valve.The manual selector valve transfers clutchpressure either to the forward clutch(position D) or to the reverse clutch(position R), depending on the selectorlever position. The non-pressurizedclutch is vented into the oil sump.In selector lever positions N and P, thesupply is shut off via the manual selectorvalve and both clutches are vented intothe oil sump.

ReverseClutch

ManualSelectorValve

ForwardClutch

SafetyValve

Pressure ControlValve -1- for AutomaticTransmission N215

PilotPressureValve

ClutchControlValve

P R N D

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ATF Depressurized

Clutch PressureSupply Pressure

Pilot Control PressureControl Pressure

In the Oil Sump

18

Modules

Safety Shut-Off

A safety-critical malfunction has occurredif actual clutch pressure is clearly higherthan specified clutch pressure. In this case,the clutch is depressurized regardless ofthe manual selector valve position andother system states.

A safety shut-off is implemented viathe safety valve and enables the clutchto open quickly.

The safety valve is activated by SolenoidValve 1 N88. At control pressures aboveapproximately 58 psi (400 kPa), the supplyto the clutch control valve is shut off andthe connection to the manual selectorvalve in the oil sump is vented.

Overload Protection

Using a model calculation, the TransmissionControl Module J217 calculates the clutchtemperature from clutch slip, engine torqueto be transmitted, and transmission oiltemperature. Engine torque is reduced ifthe measured clutch temperature exceedsa defined threshold because of excessload on the clutch.

Engine torque can be reduced to the upperend of the idling speed range. It is possiblethat the engine will not respond to theaccelerator pedal for a short period of time.The clutch cooling system ensures a shortcooling-down time. Maximum enginetorque is quickly available again. Overloadof the clutch is almost impossible.

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Switched Position After Safety Shut-Off

Vented into Oil Sump/Depressurized

Clutch Pressure

Supply Pressure

Pilot Control Pressure

Control pressure

In the Oil Sump

ForwardClutch

ManualSelectorValve

SafetyValve

ClutchControlValve

SolenoidValve 1N88

P RN D

ReverseClutch

19

Modules

Clutch Control when Vehicle

Is Stationary (Slip Control)

The slip control function sets the clutch to adefined slip torque (clutch torque) when theengine is running at idling speed and a driveposition is selected. The vehicle behaves inthe same way as an automatic transmissionwith a torque converter.

Selective clutch pressure adaptation resultsin an input torque which causes the vehicleto ”creep.”

Input torque is varied within defined limitsdepending on vehicle operating state andvehicle road speed. The contact pressureapplied by the taper pulleys is sensed byAutomatic Transmission Sender -2- forHydraulic Pressure G194. This informationis used for precision clutch torque control.

BrakePedal NotPressed

Because contact pressure is proportional tothe actual engine input torque presentat pulley set 1, clutch torque can beprecisely calculated and controlled usingAutomatic Transmission Sender -1- forHydraulic Pressure G193 (for more detailedinformation, refer to “The Torque Sensor,”page 33).

Slip control allows the vehicle tobe maneuvered when parkingwithout pressing the acceleratorpedal and therefore enhancesdriving comfort.

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Automatic TransmissionSender -1- forHydraulic Pressure G193

29.5 psi(40 Nm)


20

Modules

Special Feature of the Slip Control

A special feature of the slip control isthe reduction of slip torque when thevehicle is stationary and the brakes areactuated. As a result, the engine is notrequired to develop so much torque (theclutch is also open wider).

This has a positive effect on fuel economy.Noise from the engine running at idlespeed when the vehicle is stationary isreduced and much less pressure has tobe applied to the brake pedal to stopthe vehicle.

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11.1 psi(15 Nm)

If the vehicle rolls back when standingon a slope with only light pressureapplied to the brake, the clutch pressureis increased to immobilize the vehicle (“hill-holder” function).

By using two transmission output speedsenders (Sender for Transmission OutputRPM G195 and Sender -2- for TransmissionOutput RPM G196) it is possible todistinguish between forward travel andreverse travel, which makes the hill-holderfunction possible (for further information,please refer to “Sensors,” page 63).

BrakePedalPressed



0 (0)

37 (50)

74 (100)

111 (150)

148 (200)

184 (250)

221 (300)

10000 2000 3000 4000 5000 6000 7000

Eng

ine

Torq

ue in

lbs-

ft (N

m)

21

Modules

The Micro-Slip Control

The micro-slip control serves to adapt theclutch control (see description of adaptationprocess, page 22) and dampen the torsionalvibration induced by the engine.

In the part-throttle range, the clutchcharacteristics are adapted up to an enginetorque of 118 lbs-ft (160 Nm).

In the engine speed range up toapproximately 1800 rpm and at enginetorques up to approximately 162 lbs-ft(220 Nm), the clutch operates in what isknown as “micro-slip” mode. In thisoperating mode, a slip speed (speeddifferential) of approximately 5 rpm to 20rpm is maintained between thetransmission input shaft and pulley set 1.

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For this purpose, the Transmission ControlModule J217 compares the signalgenerated by Sensor for Transmission RPMG182 with the engine speed, makingallowance for the auxiliary reduction gearstep. Sensor for Transmission RPM G182registers the rotation of pulley set 1.

As the term “micro-slip”suggests, clutch slip is kept ata minimum so no noticeablepenalties in lining wear and fueleconomy occur.

Engine Speed in RPM

Approximately1800 RPM

Clutch Closed

Micro-Slip Control Range

Adaptation Range During Micro-Slip Control:Up to Approximately 118 lbs-ft (160 Nm)

22

Modules

Clutch Control Adaptation

To be able to control the clutch comfortablyin any operating state and throughout itsservice life, the relationship betweencontrol current and clutch torque has to beupdated continuously.

This is necessary because thecoefficients of friction of the clutchesare constantly changing.

The coefficient of friction is dependent onthe following factors:

• Transmission oil (quality, aging, wear)

• Transmission oil temperature

• Clutch temperature

• Clutch slip

To compensate for these influences andoptimize clutch control, the relationshipsbetween control current and clutch torqueare adapted in slip control mode and in thepart-throttle range.

Adaptation in Slip Control Mode

(Brake Pressed):

As mentioned already, a defined clutchtorque is set in slip control mode.The Transmission Control Module J217observes the relationship between thecontrol current from Pressure Control Valve-1- for Automatic Transmission N215 andthe data from Automatic TransmissionSender -2- for Hydraulic Pressure G194(contact pressure) and stores these data.The actual data are used for calculatingnew characteristics.

Here, “adaptation” meanslearning new pilot control values.

Adaptation in Part-Throttle Range

In the part-throttle range, adaptation isperformed in micro-slip control mode.In this operating mode the TransmissionControl Module J217 compares the enginetorque from the Motronic Engine ControlModule J220 to the control current fromPressure Control Valve -1- for AutomaticTransmission N215 and stores these data.The actual data are used for calculatingnew characteristics (see “Micro-SlipControl,” page 21).

Summary:

The adaptation function serves to maintaina constant clutch control quality.

The adaptation data also have an effecton the calculation of clutch pressure athigher transmission torques (clutch fullypositively engaged).

High clutch pressures are not required,which ultimately has a positive effecton efficiency.

23

Modules

The Clutch Cooling System

The clutches are cooled by a separateoil flow in order to protect them fromexposure to excessively high temperatures(particularly when driving away underhard acceleration).

To minimize power losses due to clutchcooling, the cooling oil flow is directedwhere it is needed by a cooling oil controlmodule integrated into the valve body.

Additional cooling oil is supplied by asuction jet pump (entrainment pump)without placing a demand on oil

Forward Clutch

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pump capacity.

To optimize clutch cooling, the cooling oilflows only to the power-transmitting clutchpulley set.

The cooling oil and the pressurized oil ofthe forward clutch flow through the hollowtransmission input shaft. The two oilcircuits are separated from one another bya steel tube, the “inner part.”

An “oil divider” located at the oil outletbores on the transmission input shaftguides the cooling oil flow to the forwardclutch and the reverse clutch.

Oil Divider withDiaphragm Spring andStop Ring with Openings

Diaphragm SpringDistributor Disc

Inner Part

Stop Ring

Oil Divider

Reverse Clutch

24

Modules

Cooling the Forward Clutch

If the forward clutch is engaged, thecylinder (thrust plate) of the forward clutchpresses the oil divider back.

In this position, the cooling oil flows pastthe front face of the oil divider and throughthe forward clutch.

Cooling the Reverse Clutch

If the forward clutch is not operated(when the engine is running at idling speedor when the reverse clutch is operated),the oil divider is in its basic position.

In this position, the cooling oil flows to theoil divider and is rerouted to the reverseclutch by a distributor plate. Branches in thedistributor pulley duct cooling oil to theplanetary gear train and provide thenecessary lubrication there.

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Forward Clutch Reverse Clutch

Cylinder

Oil Pressure for Clutch

Clutch Cooling Oil Flow

25

Modules

Hydraulic Clutch Cooling Control

The clutch cooling system cuts inat the same time as the clutch controlis activated.

The Transmission Control Module J217applies a defined control current toSolenoid Valve 1 N88. This produces acontrol pressure which switches the clutchcooling valve.

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The clutch cooling valve transfers pressurefrom the cooler return pipe to the suctionjet pump (entrainment pump).

The pressurized oil is used to operate thesuction jet pump (entrainment pump) (forfurther details, refer to “The Suction JetPump (Entrainment Pump),” page 46).


Control Pressure

In the Oil Sump

To Manual Selector Valve

To Cooler Return Pipe

SafetyValve

SolenoidValve 1N88

Pressure ControlValve -1- for AutomaticTransmsiion N215

ClutchCoolingValve

PilotPressureValve

Suction Jet Pump(Entrainment Pump)with Check Valve

To theClutches

ATF Depressurized

Cooling Oil Flow

Oil from Cooler Return Pipe

26

Modules

The Auxiliary Reduction Gear Step

Due to constraints on space, torque istransmitted to the Variator through anauxiliary reduction gear step.

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The auxiliary reduction gear step hasdifferent reduction ratios to accommodatedifferent engines to the transmission. As aresult, the Variator is operated within itsoptimum torque range.

PlanetaryGear Train

Pulley Set 1

Auxiliary ReductionGear Step

27

Modules

The Variator

The basic operating principle of theVariator has been explained on page 3. Thespecial features and functions of themultitronic® Variator are described on thefollowing pages.

The Concept of the Variator Used in the

multitronic®

The operation of the Variator is based onwhat is known as the dual-piston principle.A special feature of the multitronic®Variator is the torque sensor integrated inpulley set 1 (for more detailed informationrefer to “The Torque Sensor,” page 33).

Pulley sets 1 and 2 each have a separatepressure cylinder for pressing the taperpulleys as well as a separate variabledisplacement cylinder for transmissionratio adjustment.

The dual-piston principle makes it possibleto change the transmission ratio veryquickly by applying a small amount ofpressure. This ensures that the taperpulleys maintain sufficient contact pressureat a relatively low oil pressure level.

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Starting Torque Ratio

Pulley Set 2

Pulley Set 1

ChainTorque Sensor

28

Modules

Adjustment

A suitable supply of pressurized oil isrequired due to the heavy demands on theadjustment dynamics. To minimize therequired quantity of oil, the variabledisplacement cylinders have a smallersurface area than the pressure cylinders.Therefore, the quantity of oil needed foradjustment is relatively small.

This makes high adjustment dynamics andhigher efficiency possible despite the lowdelivery rate of the oil pump.

The diaphragm springs in pulley set 1and the coil springs in pulley set 2 createa defined basic chain tension (contactpressure) when the hydraulic systemis depressurized.

In the depressurized state, the Variatorfor the starting torque ratio is adjusted bythe spring force of the coil springs inpulley set 2.

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End Torque Multiplication Ratio (Overdrive)

Pressure Cylinder Diaphragm Spring

Torque Sensor Variable Taper Pulley

Pulley Set 1

VariableDisplacementCylinder

Pulley Set 2

Variable Taper PulleyPressure Cylinder

Pressure Spring

VariableDisplacementCylinder

29

Modules

Contact Pressure

High contact pressures are requiredbetween the taper pulley and the chain totransmit the torque the engine develops.The contact pressure is produced byadjusting the oil pressure in the pressurecylinder as appropriate.

According to the principles of hydraulics, aresultant force (contact pressure) can bevaried as a function of pressure andeffective area.

The pressure cylinders have a largersurface area and can therefore apply therequired contact pressure with less oilpressure. The relatively low oil pressure isalso more efficient.

Towing

When the vehicle is being towed, pulley set2 drives pulley set 1 and there is a dynamicpressure buildup in the variabledisplacement cylinder and pressure cylinderof the pulley sets.

The system is designed in such a waythat the reduction ratio is adjusted toapproximately 1:1 by the dynamic pressurebuild-up in the Variator. Pulley set 1 andthe planetary gear train are thus protectedfrom excessively high engine speeds.

The diaphragm springs in pulley set 1 assistwith this process.

For more detailed informationregarding dynamic pressurebuild-up, refer to “The SplashOil Cover,” page 38.

Also observe the towinginformation given in “Towing,”page 91.

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DiaphragmSpring inPulley Set 1

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Resultant Force1124 lbs (5 000 N)

Effective Area15.50 in2

(100 cm2)

Pressure72.5 psi(500 kPa)

Resultant Force1124 lbs (5 000 N)

Effective Area7.75 in2 (50 cm2)

Pressure 145 psi(1 000 kPa)

30

Modules

The Transmission Control

Electronic Control

The Transmission Control Module J217has a dynamic control program forcalculating the nominal transmission inputspeed. It is an improved version of thedynamic shift program (DSP) already beingused in multi-step automatic transmissions.The driver input and vehicle operating stateare evaluated to provide the best gear ratioin every driving situation (see “DynamicControl Program,” page 82).

The dynamic control program calculates anominal transmission input speeddepending on conditions.

The Sensor for Transmission RPM G182registers the actual transmission inputspeed at pulley set 1.

The Transmission Control Module J217calculates a control current for PressureControl Valve -2- for AutomaticTransmission N216 based on an actual-value/setpoint comparison. PressureControl Valve -2- for AutomaticTransmission N216 produces a controlpressure for the hydraulic reduction valvewhich is almost proportional to thecontrol current.

Transmission control is monitored bychecking the plausibility of the signals fromSensor for Transmission RPM G182 andSender for Transmission Output RPM G195as well as the engine speed.

SSP 228/076

TransmissionControl Module J217

Pressure Control Valve -2- forAutomatic Transmission N216

Sensor forTransmissionRPM G182

Sender forTransmissionOutput RPM G195

31

Modules

SSP 228/076

Hydraulic Transmission Control

Pressure Control Valve -2- for AutomaticTransmission N216 is supplied witha constant pressure of approximately73 psi (500 kPa) by the pilot pressurevalve. Pressure Control Valve -2- forAutomatic Transmission N216 producesa control pressure corresponding tothe control current calculated by theTransmission Control Module J217, whichinfluences the position of the hydraulicreduction valve.

A high control current leads to a highcontrol pressure.

The hydraulic reduction valve transfersthe adjusting pressure to the variabledisplacement cylinder of pulley set 1 or 2,depending on the control pressure.

Pulley Set 1


Pulley Set 2

HydraulicReductionValve

PressureControl Valve-2- forAutomaticTransmissionN216

PilotPressureValve

From theOil Pump

Vented into Oil Sump

Oil Supply


Control Pressure

In the Oil Sump

32

Modules

The hydraulic reduction valve is closed at acontrol pressure of between approximately26 and 32 psi (180 and 220 kPa). At a controlpressure of less than 26 psi (180 kPa), theadjusting pressure is transferred to variabledisplacement cylinder at pulley set 1, andthe variable displacement cylinder of pulleyset 2 is simultaneously vented to theoil sump. The Variator shifts the reductionratio towards the end torque multiplictionratio (overdrive).

If the control pressure is greater than32 psi (220 kPa), the adjusting pressure istransferred to the variable displacementcylinder at pulley set 2 and the variabledisplacement cylinder at pulley set 1 issimultaneously vented to the oil sump.The Variator shifts the reduction ratiotowards the starting torque ratio.

SSP 228/084

End Torque Multiplication Ratio (Overdrive)

Pulley Set 1

Pulley Set 2

HydraulicReductionValve

PressureControlValve -2- forAutomaticTransmissionN216

PilotPressureValve

From the Oil Pump

Vented into Oil Sump

Oil Supply


Control Pressure

In the Oil Sump

33

Modules

The Torque Sensor

Contact Pressure Control

As mentioned before, a suitable oilpressure in the pressure cylinder gives aresultant contact pressure of the taperpulleys. If the contact pressure is too low,slippage of the chain will occur and thechain and pulley sets will be damaged. Anexcessively high contact pressure, on theother hand, will result in loss of efficiency.

The object, therefore, is to set the contactpressure of the taper pulleys as accuratelyand safely as possible according torequirements.

RampShell 1

SSP 228/021

A hydro-mechanical torque sensorintegrated in pulley set 1 statically anddynamically registers the actual torquetransmitted to a high degree of accuracyand sets the correct oil pressure in thepressure cylinders.

The engine torque is transferredto the Variator by the torquesensor only. The contact pressureis controlled hydro-mechanicallyby the torque sensor.

Ramp Shell 2

Pulley Set 1

RampShell 2

34

Modules

Design and Function

The torque sensor essentially comprisestwo shells with seven ramps betweenwhich steel balls are mounted in bearings.Ramp shell 1 is form-fitted to the outputgear of pulley set 1 (output gear wheel ofauxiliary reduction gear step). Ramp shell 2is connected to pulley set 1 by a groovedgearing that allows axial movement and issupported by the torque sensor piston. Thetorque sensor piston serves to regulate thecontact pressure and houses torque sensorspaces 1 and 2.

The shells can be rotated radiallytowards one another, converting thetorque to an axial force (due to the balland ramp geometry).

This axial force acts upon ramp shell 2 andmoves the torque sensor piston which is incontact with the shell.

The control edge of the torque sensorpiston now closes or opens the outlets intorque sensor space 1.

The axial force generated by thetorque sensor serves as a controlforce which is proportional to theengine torque.

The pressure which builds upin the pressure cylinder isproportional to the control force.

SSP 228/022

Torque Sensor Piston

Torque Sensor Space 1

Torque Sensor Space 2

Ramp Shell 1

Grooved Gearing

Ramp Shell 2

35

Modules

Torque sensor space 1 is directly connectedto the pressure cylinder.

The system is designed so the axial forcegenerated as a product of engine torqueand the pressure in the pressure cylinderform a force equilibrium.

In constant conditions of vehicle operation,the outlet bores are only partially closed.The pressure drop produced by opening theoutlet bores (torque sensor) modulates thepressure in the pressure cylinder.

If input torque increases, the outlet boresare initially closed further by the controledge. The pressure in the pressure cylinderrises until a force equilibrium again exists.

If input torque decreases, the outlet boresare opened further. The pressure in thepressure cylinder decreases until the forceequilibrium is restored.

SSP 228/057

PressureCylinder

SSP 228/056

Torque SensorSpace 1

OutletBore

PressureCylinder

ControlEdge

OutletBore

100

75

50

25

02.4 1 0.4

36

Modules

At peak torque levels, the control edgecloses off the outlet bores. If the torquesensor moves any further, it acts as an oilpump. The displaced oil volume causes arapid rise in the pressure inside thepressure cylinder and immediately adjuststhe contact pressure.

Extremely high peak torques canoccur when the vehicle drivesover a pot-hole or if thecoefficient of friction of the roadsurface fluctuates considerably(transitions from black ice toasphalt for example).

Adaptation of contact pressure

depending on transmission ratio

The contact pressure exerted by the taperpulleys depends not only on the inputtorque but also on chain track radius and,therefore, on the actual reduction ratio ofthe Variator.

As the diagram shows, the starting torqueratio (clutch engagement) requires thegreatest contact pressure.

The radius of the chain is smallest in pulleyset 1. For power transmission, only a smallnumber of cradle type pressure pieces arein mesh despite the high input torque.

Therefore, a higher contact pressure isapplied by the taper pulleys until a definedreduction ratio of 1:1 is exceeded.

OutletBore

SSP 228/046

SSP 228/058

PressureCylinder

Con

tact

Pre

ssur

e in

%

Required Contact Pressurefor 25% Torque Requirement

VariatorRatio

Overdrive


Overdrive


Required Contact Pressurefor 100% Torque Requirement

Contact Pressure

37

Modules

Function and Mode of Operation

The ratio-dependent contact pressureis adapted in torque sensor space 2.The pressure level in the pressure cylinderis varied by increasing or decreasing thepressure in torque sensor space 2.The pressure in torque sensor space 2is controlled by two transverse holes inthe shaft of pulley set 1. These holes areopened or closed through axialdisplacement of the variable taper pulley.

The transverse holes are open when theVariator is in the starting torque ratio(torque sensor space 2 is depressurized).

When the Variator changes the ratioto end torque multipliction ratio (overdrive),the transverse holes are shut off initially. Ata defined reduction ratio, the left-handtransverse hole is opened to the pressurecylinder through corresponding holes in thevariable taper pulley.

This allows the oil pressure to betransferred from the pressure cylinder intotorque sensor space 2. This pressurecounteracts the axial force of the torquesensor and moves the torque sensor pistonto the left.

The control edge opens up the outlet boresfurther, reducing the oil pressure inside thepressure cylinder.

The main advantage of the two-stagepressure adaptation process is that a lowcontact pressure can be utilized in themid-ratio range which increases efficiency(refer to illustration SSP 228/046,previous page).

SSP 228/060

Torque Sensor Piston

SSP 228/059

Transverse HolesTorque Sensor Space 2

Variable Taper Pulley

Torque Sensor Space 2Bore

Bore

38

Modules

The Splash Oil Cover

Another special feature of the Variator isthe “splash oil cover” on pulley set 2 whichcounteracts the dynamic pressure buildupin the pressure cylinder.

At high engine speeds, the transmission oilin the pressure cylinder is subjected to highrotation-induced centrifugal forces, whichleads to a rise in pressure. This process isknown as “dynamic pressure buildup.”

A dynamic pressure buildup is undesirablebecause it unduly increases the contactpressure and has an adverse effect ontransmission control.

The oil confined in the splash oil cover issubjected to the same dynamic pressurebuildup as in the pressure cylinder. Thedynamic pressure buildup in the pressurecylinder is compensated by this.

The splash oil chamber receives its oilsupply directly from the hydraulic controlmodule through an oil injection hole. Oil iscontinuously injected into the splash oilchamber inlet through this hole.

A reduction in volume inside the splash oilchamber (when varying the transmissionratio) causes the oil to be dischargedthrough the supply inlet.

SSP 228/061

Oil Injection Hole

Splash Oil CoverPulley Set 2

Pressure Cylinder

Splash Oil Chamber

39

Modules

The Chain

The chain is a key component part of theVariator of the multitronic®.

This is the first time that a chain has beenused as a driving means in a CVT.

The chain is a new development and hasthe following advantages over conventionaldriving means such as sliding link beltsor V-belts:

• Very small track radii make possible alarge “spread” despite the small size ofthe Variator.

• High transferable torque.

• High efficiency.

Pulley Set 1

SSP 228/026

The spread indicates the rangeof ratios which a transmissionprovides.

The spread is specified as a ratio.The starting torque ratio dividedby the spread equals to the endtorque multiplication ratio.In general a large spread is anadvantage because both a highstarting torque ratio (for goodperformance) and a low endtorque multiplication ratio (for lowfuel consumption) are available.This applies in particular to theCVT concept, since practicallyall intermediate steps areavailable and no ratio steps areout of place.

Pulley Set 2

Chain

40

Modules

Design and Function

On a conventional chain, the chain linkplates are interconnected by joint pins witha slip fit. For torque transmission, gearteeth move into engagement with the pinsbetween the chain link plates.

The CVT chain uses a

different technology.

The CVT chain has adjacent rows of chainlink plates linked continuously with cradletype pressure pieces (two per link).

On the CVT chain, the cradle type pressurepieces are “jammed” between the taperpulleys of the Variator as the taper pulleysare pressed toward one another.

The torque is transmitted only by thefrictional force between the ends of thecradle type pressure pieces and thecontact faces of the taper pulleys.

This is how it works:

Each of the cradle type pressure pieces ispermanently connected to a row of linkplates so that it cannot be twisted.Two cradle type pressure pieces form acradle type joint.

The cradle type pressure pieces now roll offone another with very little friction as they“drive” the chain within the track radius ofthe taper pulleys.

In this way, lost power and wear areminimized despite the high torque and thelarge angle of bend. The result is longservice life and optimal efficiency.

Cradle TypePressure Piece

SSP 228/027

Taper Pulley of the Variator

Cradle TypePressure Pieces

Top

View

Shackle

Side

View

CradleType Joint

41

Modules

Acoustic Measures

Two different lengths of link plate are usedto ensure that the chain runs as quietlyas possible.

When using a constant length oflink plate, the cradle type pressurepieces strike the taper pulleys at uniformintervals and induce vibrations which causea noise nuisance.

Using different lengths of link platecounteracts resonance and minimizesrunning noise.

SSP 228/028

Different Lengthsof Link Plate

42

Modules

The Oil Supply

In the multitronic®, power transmission isdependent on the electrical power supplyand also on the hydraulics.

In order to work, an electric current and

adequate oil supply are required.

The oil pump is the main power consumerin the transmission and its capacity isimportant for overall efficiency.

The transmission control and coolingsystems are designed to run on a minimumof oil, and an innovative oil supply systemhas been developed.

Intake Filter

The Oil Pump

The oil pump is mounted directly on thehydraulic control module to avoidunnecessary interfaces. The oil pumpand the control module form a compactunit, which reduces pressure losses andproduction costs.

The multitronic® is equipped with anefficient crescent pump. This pumpproduces the necessary pressures, butrequires only a relatively small quantity ofoil. A suction jet pump (entrainment pump)supplies the additional quantity of oilrequired for the clutch cooling at lowpressure. The compact crescent-vanepump is integrated in the hydraulic controlmodule and driven directly by the inputshaft by a spur gear and pump shaft.

SSP 228/034

HydraulicControl Module(Valve Body)

Pressure Tube Routedto Suction Jet Pump(Entrainment Pump)

Oil Pump

43

Modules

As a special feature, the oil pump has axialand radial clearance adjustment.

A pump with good “internal sealing” isrequired in order to produce high pressuresat low engine speeds.

“Internal sealing” refers to theability of the pump to minimizeleakage past the surfaces movingthe fluid through the pump.

SSP 228/035Axial Plates

Conventional oil pumps do not meetthese requirements due to componenttolerances.

The axial clearance between the gearsand the housing, as well as the radialclearance between the gears and thecrescent vane can vary depending on thetolerance zone position of the componentparts in a conventional pump.

The pressure generated can thus more orless escape “internally.”

The result will be a loss of pressure and adrop in efficiency.

Segmental SpringsSealing Roller

Stop PinInner Segment

Spring Rod

Oil Pump Housing

Outer Segment

Driver

44

Modules

Axial Clearance Adjustment

Two axial plates cover the pressure rangeof the crescent pump and form a separatedischarge casing inside the pump.They seal the pump pressure chamberlaterally (axially). These plates, fitted witha special seal, are supported by the oilpump housing or the pump plate of thehydraulic control module.

The axial plates are designed to allow thepump pressure to act between the axialplates and the housing. The seal preventspressure from escaping. As pump pressure

SSP 228/051

increases, the axial plates are pressedmore firmly against the crescent seal andthe pump gears, which compensates foraxial clearance.

The axial and radial clearanceadjustment allows the pump togenerate the required highpressures and simultaneouslyachieve high efficiency despite itscompact design.

Seal

Axial Plate

Oil Pump Housing

Axial Plate

Axial Plate

45

Modules

Radial Clearance Adjustment

The radial clearance adjustment featurecompensates for the radial gap betweenthe crescent seal and the gears (pinion andring gear).

For this purpose, the crescent seal is splitin two segments, the inner segment andthe outer segment.

The inner segment seals the pressurechamber off from the pinion. It also holdsthe outer segment in a radial direction.The outer segment seals the pressurechamber off from the ring gear. The pumppressure flows between the two

SSP 228/049

Inner Segment

segments. The segments are pressedmore firmly against the pinion and ring gearas the pump pressure increases, whichcompensates for radial clearance.

When the pump is depressurized, thesegmental springs provide the basiccontact pressure for the segments and thesealing roller, and improve the suctioncharacteristics of the oil pump.

They also ensure that the pump pressurecan act between the segments and on thesealing roller.

Crescent SealOuter Segment

Pinion

Ring Gear

46

Modules

The Suction Jet Pump

(Entrainment Pump)

The quantity of oil required to ensuresufficient cooling of the two clutchesexceeds the capacity of the internal gearpump, particularly when pulling away(there is high heat buildup due to slip).

SSP 228/036

View of Suction Jet Pump

(Entrainment Pump)

Pressure Tube(Routed toforward clutch)

Inlet Pipe

Pressure Tube(Routed from hydrauliccontrol moduleto suction jet pump(entrainment pump))

ATF Overflow Pipe

A suction jet pump (entrainment pump) isintegrated in the clutch cooling system tosupply the quantity of oil required forcooling the clutch.The suction jet pump (entrainment pump) ismade of plastic and projects deep into theoil sump.

47

Modules

SSP 228/037

Suction Jet Pump (Entrainment Pump)

(Shown in Profile and Folded Out)

CheckValve

VenturiNozzle

This is how it works:

The suction jet pump (entrainment pump)operates according to the Venturi principle.When the clutch requires cooling, thecooling oil (pressurized oil) supplied by theoil pump is ducted through the suction jetpump (entrainment pump) in the formof a powerful jet. The oil flow through theentrainment pump nozzle results in a partialvacuum which “sucks” oil out of the oilsump and, together with the powerful jet,results in a large, almost depressurizedquantity of oil.

The quantity of cooling oil is almostdoubled as required without additionalpumping capacity.A check valve prevents the suction jetpump (entrainment pump) from running dryand facilitates a quick response of thecooling oil feed.

48

Modules

Electro-Hydraulic Control

A new feature is that theoil pump, hydraulic controlmodule (valve body) andTransmission Control ModuleJ217 are combined as acompact assembly.

Selector Shaft

The hydraulic control module containsthe manual selector valve, nine hydraulicvalves and three electromagnetic pressurecontrol valves.

The hydraulic control module and theTransmission Control Module J217 areconnected electrically by direct plug-incontacts.

SSP 228/063

Oil Pump

ManualSelectorValve


Direct Plug-In Contact

Hydraulic Control Module

49

Modules

The hydraulic control module executes thefollowing functions:

• Forward-reverse clutch control

• Clutch pressure regulation

• Clutch cooling

• Pressurized oil supply to the contactpressure control

• Transmission control

• Supplying the splash oil cover

The hydraulic control module isconnected directly to pulley set 1 andpulley set 2 by “screw inserts.”

The screw inserts are sealed by O-rings.

Screw Inserts for Pulley Set 1

SSP 228/085

Screw Inserts for Pulley Set 2

O-Ring

Oil Injection Hole forSplash Oil Cover

O-Ring

50

Modules

Sectional View of Valve Plate

SSP 228/047

The descriptions of the valves that followrefer to valves not included in the previousmodule/function descriptions:

To protect the component parts, pressure

limiting valve 1 limits the pump pressureto maximum 1189 psi (8 200 kPa).

The pressure control valves aresupplied with a constant pilot controlpressure of 73 psi (500 kPa) by thepilot pressure value.

SSP 228/044


(Transmission Control Module J217 Removed)

Connection toAutomaticTransmissionSender -1-for HydraulicPressure G193

ElectricalConnectorfor N88



PressureLimitingValve 1

Connection toAutomaticTransmissionSender -2-for HydraulicPressure G194

Pressure ControlValve -2- forAutomaticTransmissionN216

SolenoidValve 1N88

PilotPressureValve

PressureControl Valve-1- forAutomaticTransmissionN215

ClutchControlValve

MinimumPressureValve

PressureLimitingValve 1Clutch

CoolingValve

The minimum pressure valve preventsthe oil pump drawing in engine air whenthe engine is started. When pump output ishigh, the minimum pressure valve opensand allows oil to flow from the oil returnpipe to the suction side of the oil pump;this improves efficiency.

51

Modules

The pressurizing valve controls thesystem pressure so that sufficient oilpressure is always available for a particularfunction (application of contact pressureor adjustment).

Solenoid Valve 1 N88, Pressure ControlValve -1- for Automatic Transmission N215,and Pressure Control Valve -2- forAutomatic Transmission N216 are designedas “pressure control valves.”

They convert an electric control current to aproportional, hydraulic control pressure.

The Solenoid Valve 1 N88 controls theclutch cooling valve and the safety valve.Pressure Control Valve -1- for AutomaticTransmission N215 actuates the clutchcontrol valve. Pressure Control Valve -2- forAutomatic Transmission N216 actuates thereduction valve.

Sectional View of Pump Plate

ReductionValve

SSP 228/048

SafetyValve

ManualSelectorValve

VolumetricFlow RateLimiting Valve

PressurizingValve

SSP 228/100

Current in mA

SSP 228/101

Diagram of Pressure Control Valve

Con

trol

Pre

ssur

e in

psi

(kP

a)

Pressure Control Valve

(Proportional Valve)

0 (0)0 1000

73 (500)

52

Modules

Selector Shaft and Parking Lock

A mechanical connection (cable pull) fortransmission of selector lever positions P,R, N and D still exists between the gateselector lever and the transmission.

The following functions are executed viaselector shaft:

• Actuation of the manual selector valve inthe hydraulic control module, i.e.hydromechanical control of vehicleoperating state (forward/reverse/neutral).

• Operating the parking lock.

• Actuation of the multi-functional switchfor electronic recognition of the selectorlever position.

SSP 228/065

Actuation ofthe Outer SelectorMechanism

In selector lever position P, the linkagewith locking teeth is displaced axially sothat the parking lock ratchet is pressedagainst the parking lock gear and theparking lock is engaged.

The parking lock gear is permanentlyconnected to the drive pinion.

Parking Lock Ratchet

Linkage with Locking Teeth

Pulley Set 2

Detent Gate

Drive Pinion

Magnetic Gate

Parking Lock Gear

Manual Selector Valve

Selector Shaft

53

Modules

Transmission Housing Ducting

and Sealing Systems

Sheathed Sealing Ring System

The multitronic® is equipped with a newsheathed sealing ring system.

The sheathed sealing rings seal thepressure cylinder and the variable-displacement cylinder of pulley set 1,the pulley set 2, and the piston forthe forward clutch.

The O-ring presses down and seals thesheathed sealing ring.

The oil pressure present assists thesheathed sealing rings with contactpressure application.

Advantages of the sheathed sealing ringsystem:

• Good anti-friction properties

• Low displacement forces

• Wear is minimized

• Stable at high pressures

SSP 228?062

Double-Corrugated Sealing Ring

O-Ring

SheathedSealing Ring

54

Modules

To save weight, the three-piecetransmission housing is manufacturedfrom the AZ91 HP magnesium alloy.This alloy is highly corrosion resistant,easy to process and has a 17.6 lb (8 kg)weight advantage over a conventionalaluminum alloy. As a special feature,the ATF pressurized oil is not distributedthrough housing ducts as is usual onautomatic transmissions, but almostexclusively by pipes.

Axial sealing elements are used to sealthe pipe connections. The axial sealingelements of the pressure pipes have twosealing lips which apply a higher contactpressure as a result of the oil pressure, andtherefore seal the pipes reliably. Diagonalpipe connections can also be sealedwithout difficulty using this technology (e.g.pressure tube connected to reverse clutch).The oil pump intake fitting axial sealingelement has sealing beads which seal thefitting by contact pressure.

The double-corrugated sealing ring (seepage 53) separates the ATF reservoirfrom the final drive oil reservoir. It preventsthe ATF from entering the final drive andoil from the final drive entering theATF reservoir.

Leaks in the double-corrugated sealing ringbecome visible at the oil return hole.

Groove forDouble-CorrugatedSealing Ring

Inner Section

Pressure Tube Routedto Reverse Clutch

Differential PressureValve 1 withATF Strainer 1

Oil Return Hole

55

Modules

Pressure Tube Routed toSuction Jet Pump (Entrainment Pump)

SSP 228/041

Oil Drain Screw

Suction Jet Pump (Entrainment Pump)

ATF Inspection Plug

Axial Sealing Element

Pressure Tube Routed toForward Clutch

ATF Level

Intake Filter

Return Pipe from ATF Coolerwith Spray Nozzles for Chainand Pulley Sets

56

Modules

Hydraulic Circuit Diagram

23

Pulley Set 1

2 Pulley Set 2

7

3

4 5 19

22

2011

26

28

15

18 6

27

24 9

8 30

1410

13

25

31

1

29

12P R N D

21

16

SSP 228/039

32

17

57

Modules

Hydraulic Circuit Diagram Legend

(Selector Lever Position P

and Engine “OFF”)

1 Pressure Limiting Valve 12 Pressure Limiting Valve 23 Differential Pressure Valve 14 Differential Pressure Valve 25 ATF Filter6 Manual Selector Valve7 ATF Cooler8 Clutch Cooling Valve9 Clutch Control Valve

10 Minimum Pressure Valve11 Measuring Point for Contact

Pressure (Registered by G194)12 Measuring Point for Clutch Pressure

(Registered by G193)13 Solenoid Valve 1 N88

(Clutch Cooling/Safety Shut-Off)14 Pressure Control Valve -1- for

Automatic Transmission N215 (Clutch)15 Pressure Control Valve -2- for

Automatic Transmission N216 (Ratio)16 Oil Pump17 Selector Lever Position PRND18 Reverse Clutch19 ATF Strainer 120 ATF Strainer 221 ATF Strainer 322 Four Spray Holes for Pulley Set

Lubrication/Cooling23 ATF Intake Filter24 Safety Valve25 Suction Jet Pump (Entrainment Pump)26 Reduction Valve27 Forward Clutch28 Volumetric Flow Rate Limiting Valve29 Pressurizing Valve30 Pilot Pressure Value31 To Splash Oil Cover32 To the Clutches

Differential Pressure Valve 1and ATF Strainer 1

SSP 228/071

Pressure Limiting Valve 2 inthe Transmission Housing

Return Pipe fromATF Cooler

In the Oil Sump


Peripheral Components inthe Vehicle

58

Modules

ATF Cooling

The ATF coming from pulley set 1 initiallypasses through the ATF cooler. The ATFflows through the ATF filter before it isreturned to the hydraulic control module.

The ATF cooler is integrated in the radiator.Heat is exchanged with the coolant inthe engine cooling circuit (oil-coolantheat exchanger).

The differential pressure valve 1 protectsthe ATF cooler against excessively highpressures (ATF cold). When the ATFis cold, a large pressure differencedevelops between the supply line and thereturn line. When a specific pressuredifferential is reached, the differentialpressure valve 1 opens and the supply line

is short-circuited with the return line tobypass the ATF cooler. This also causesthe temperature of the ATF to rise tonormal operating temperature rapidly.

The differential pressure valve 2 openswhen the flow resistance of the ATF filter istoo high (e.g. filter blockage). This preventsthe differential pressure valve 1 fromopening and the ATF cooling system frombeing disabled by the backpressure.

If the ATF cooler is leaky, coolantcan enter the ATF. Even smallquantities of coolant in the ATFcan have an adverse effect onclutch control.

SSP 228/090

Peripheral Components in the Vehicle

To HydraulicControl Module

ATF Filter

multitronic®

PressureLimitingValve 2

Supply Line

ATF Cooler

ATF FilterReturn LineDifferential

PressureValve 2

ATF Strainer 1

DifferentialPressureValve 1

FromPulleySet 1

Supply Line

Return Line

59

Control

Transmission Control Module J217

A special feature of multitronic® is theintegration of the electronic TransmissionControl Module J217 in the transmission.

The control module is attached directly tothe hydraulic control module with bolts.

The connection to the three pressureregulating valves is made directly from thecontrol module by means of robust plug-incontacts (gooseneck contacts); there areno wiring connections. A 25-pin compactconnector forms the interface tothe vehicle.

A further new feature is the integration ofsensor technology in the control module.

• Multi-Function TransmissionRange Switch F125

• Sensor for Transmission RPM G182• Sender for Transmission

Output RPM G195• Sender -2- for Transmission

Output RPM G196• Transmission Fluid Temperature

Sensor G93• Automatic Transmission Sender -1-

for Hydraulic Pressure G193(Clutch Pressure)

• Automatic Transmission Sender -2-for Hydraulic Pressure G194(Contact Pressure)

SSP 228/055

Plug-In Contact forSolenoid Valve 1 N88


Sender for Transmission Output RPM G195 andSender -2- for Transmission Output RPM G196

Plug-In Contact for PressureControl Valve -1- for AutomaticTransmission N215

AutomaticTransmissionSender -1- forHydraulicPressure G193(Clutch Pressure)

Multi-FunctionTransmissionRange SwitchF125

Plug-In Contactfor Pressure ControlValve -2- for AutomaticTransmission N216(Concealed by Sensorfor TransmissionRPM G182)

Automatic Transmissionfor Sender -2-Hydraulic Pressure G194(Contact Pressure)


60

Control

A strong aluminium plate acts as thebase for the electronics and serves todissipate heat. The housing is made ofplastic and securely riveted to the base.It accommodates all the sensors, so neitherwiring nor plug-in contacts are necessary.

Since the majority of electrical failures areattributable to faulty wiring and plug-incontacts, this construction offers a veryhigh degree of reliability.

Sensor for Transmission RPM G182,Sender for Transmission Output RPMG195, Sender -2- for TransmissionOutput RPM G196, and Multi-FunctionTransmission Range Switch F125 are alldesigned as Hall sensors.

SSP 228/077

Hall sensors are free of mechanical wear.Their signal is immune to electromagneticinterference, which improves their reliabilitystill further.

Because there are only a fewinterfaces to the TransmissionControl Module J217, themultitronic® does without aseparate wiring harness.The wiring is integrated in theengine harness.

25-Pin Connector

Transmission FluidTemperature Sensor G93

Sensor forTransmissionRPM G182(One Hall Sensor)

Multi-FunctionTransmission RangeSwitch F125(Four Hall Sensors)Sender for Transmission Output RPM G195

and Sender -2- for Transmission OutputRPM G196 (Two Hall Sensors)

61

Control

Fault Indication

Faults in the multitronic® are registeredby the self-diagnosis function. Faults areindicated to the driver on the selector leverposition indicator in the instrument clusterbased on their effect on multitronic®operation or on driving safety. In this case,the selector lever position indicator alsoserves as a fault indicator.

Faults are registered by the multitronic®

three different ways:

1. The fault is stored and a substituteprogram enables continued operationof the vehicle with some restrictions.This state is not indicated to the driver,since it is not critical with regard todriving safety or multitronic® operation.The driver may notice the fault by theway the vehicle handles and seek theassistance of an Audi dealer.

2. The fault is stored and a substituteprogram enables continued operationof the vehicle with some restrictions.The selector lever position indicatoralso indicates the presence of a faultby inverting the display. The situationis still not critical for driving safety or formultitronic® operation. However, thedriver should take the vehicle to an Audidealer as soon as possible to have thefault rectified.

SSP 228/102

SSP 228/103

62

Control

3. The fault is stored and a substituteprogram enables continued operation ofthe vehicle with some restrictions, atleast until it stops. The selector leverposition indicator indicates the presenceof a fault by flashing. This state iscritical with regard to driving safety ormultitronic® operation. Therefore, thedriver is advised to take the vehicle to anAudi dealer immediately to have the faultrectified.

In some cases when thedisplay is flashing, vehicleoperation will only bemaintained until the nexttime the vehicle stops.The vehicle can subsequentlyno longer be driven! In othercases, vehicle operationcan be resumed by restartingthe vehicle.

SSP 228/104

63

Control

Sender for Transmission OutputRPM G195 and Sender -2- forTransmission Output RPM G196

Sensors

The signals generated by the sensors cannot be measured with conventionalequipment because the control module isintegrated into the transmission. A checkcan only be performed with the VehicleDiagnosis, Test and Information SystemVAS 5051 using the following functions:

• 02 — Interrogate fault memory

• 08 — Read measured value block

This Self-Study Program does not describethe sensor signals in detail.

If a sensor fails, the Transmission ControlModule J217 generates substitute valuesfrom the signals of other sensors as wellas the information from the networkedcontrol modules. Vehicle operation canthus be maintained.

The effects on vehicle performance areso small that the driver may not noticethe failure of a sensor immediately.An additional fault can, however, haveserious effects.

The sensors are an integral partof the Transmission ControlModule J217. If a sensor fails,the entire control module mustbe replaced.

Sensor for Transmission RPM G182,

Sender for Transmission Output RPM G195, and

Sender -2- for Transmission Output RPM G196

SSP 228/078

Sender Wheelfor G182Sender Wheel for

G195 and G196


64

Control

Sensor for Transmission RPM G182

registers the rotation speed of pulley set 1and therefore represents the actualtransmission input speed.

Transmission input speed...

... is used together with engine speedfor clutch control (for more detailedinformation, refer to “The Micro-SlipControl,” page 21).

... serves as the reference input variable fortransmission control (for more detailedinformation, refer to “The TransmissionControl,” page 30).

Effects of failure of Sensor for

Transmission RPM G182:

• The clutch engagement is controlledaccording to fixed parameters.

• The micro-slip control and the clutchadaptation function are deactivated.

Engine speed is used as a substitute value.

Fault indication: none

Sender for Transmission Output RPM

G195 and Sender -2- for Transmission

Output RPM G196 register the rotationspeed of pulley set 2 and with it thetransmission output speed.

The signal from Sender for TransmissionOutput RPM G195 is used for registeringrotation speed. The signal from Sender -2-for Transmission Output RPM G196 is usedfor recognition of direction of rotation andtherefore also for distinguishing betweenforward travel and reverse travel (refer to“Clutch Control when Vehicle Is Stationary(Slip Control),” page 19).

“Transmission output speed” is used...

... for transmission control,

... for slip control,

... for the hill-holder function,

... for determining the road speed signal forthe instrument cluster.

If the Sender for Transmission Output RPMG195 fails, the transmission output speedis determined from the signal fromSender -2- for Transmission Output RPMG196. The hill-holder function isdeactivated also.

If Sender -2- for Transmission Output RPMG196 fails, the hill-holder function isdeactivated.

If both senders fail, a substitute value isgenerated from the information availableon wheel speeds across the CAN bus.The hill-holder function is deactivated.


Sender Wheels

A magnetic ring with a row of magnetsis located on the end face of each senderwheel; the magnets act as north/southpoles.

• Sender wheel for Sensor forTransmission RPM G182has 40 magnets.

• Sender wheel for Sender forTransmission Output RPM G195 andSender -2- for Transmission OutputRPM G196 has 32 magnets.

Heavy contamination of themagnetic ring from metal swarfcaused by wear can impair theperformance of these senders.Therefore, metal swarfadhering to the magnetic ringshould be removed beforeperforming other repairs.

65

Control

Sender Wheel

SSP 228/109

N S N S N

Signal from Sender forTransmission Output RPM G195

1st Phase = 100%

25%

Sender -2- forTransmissionOutput RPM G196

Sender forTransmissionOutput RPM G195

How the Direction

of Rotation Is Registered:

A magnetic ring comprising a row of 32individual magnets (north/south poles) islocated on the end face of the senderwheel for Sender for Transmission OutputRPM G195 and Sender -2- for TransmissionOutput RPM G196.

The position of Sender for TransmissionOutput RPM G195 relative to Sender -2-for Transmission Output RPM G196 isoffset so that the phase angles of thesender signals are 25% out of phasewith one another.

The direction of rotationis registered for thehill-holder function.

After ignition “ON,” the control moduleobserves the falling edges of the signalsfrom the two senders and records thelevels of the other senders.

As shown in the example, the level ofSender -2- for Transmission Output RPMG196 is “low” at the falling edge of the

signal from Sender for Transmission OutputRPM G195, and the level of Sender forTransmission Output RPM G195 is “high”at the falling edge of the signal from Sender-2- for Transmission Output RPM G196.The Transmission Control Module J217interprets this “pattern” as forward travel.

SSP 228/110

Forward Travel

High

Low

High

Low

Sender forTransmissionOutput RPMG195

Sender -2- forTransmissionOutput RPMG196

Direction of Rotationof Sender Wheel

66

Control

Reverse Travel

Direction of Rotationof Sender Wheel

SSP 228/111

Low

High

Low

High

In this example, the level of Sender -2- forTransmission Output RPM G196 is “high”at the falling edge of the signal from Senderfor Transmission Output RPM G195 and thelevel of Sender for Transmission Output

RPM G195 is “low” at the falling edge ofthe signal from Sender -2- for TransmissionOutput RPM G196. The TransmissionControl Module J217 interprets this“pattern” as reverse travel.

67

Sender forTransmissionOutput RPMG195

Sender -2- forTransmissionOutput RPMG196

Control

68

Control

Automatic Transmission Sender -1- for

Hydraulic Pressure G193

Automatic Transmission Sender -1- forHydraulic Pressure G193 registers theclutch pressure of the forward- andreverse-gear clutches and is used formonitoring the clutch function(see “The Clutch Control,” page 15).

Clutch pressure monitoring has a highpriority, so malfunctioning of AutomaticTransmission Sender -1- for HydraulicPressure G193 usually causes the safetyvalve to be activated (see “Safety Shut-Off,” page 18).

Fault indication: flashing

Automatic Transmission Sender -2- for

Hydraulic Pressure G194

Automatic Transmission Sender -2- forHydraulic Pressure G194 registers thecontact pressure, which is regulated by thetorque sensor. As the contact pressure isalways proportional to the actualtransmission input torque, the transmissioninput torque can be calculated veryaccurately using Automatic TransmissionSender -2- for Hydraulic Pressure G194.

The signal from Automatic TransmissionSender -2- for Hydraulic Pressure G194 isused for clutch control (control andadaptation of the slip function).If Automatic Transmission Sender -2- forHydraulic Pressure G194 malfunctions, theslip control adaptation function isdeactivated. The slip torque is thencontrolled by means of stored values.


SSP 228/093

Automatic Transmission Sender -1-for Hydraulic Pressure G193

SSP 228/094

Automatic Transmission Sender -2- forHydraulic Pressure G194

69

Control

Multi-Function Transmission

Range Switch F125

Multi-Function Transmission Range SwitchF125 has four Hall sensors which arecontrolled by the magnetic gate on theselector shaft. The signals from the Hallsensors are interpreted in the same way asthe positions of mechanical switches.A high level means: switch is closed (1).A low level means: switch is open (0).Therefore, a Hall sensor “switch”generates two signals: “1” and “0.”

Sixteen different gearshift combinationscan be generated with four Hall sensors:

• four gearshift combinations for therecognition of selector lever positionsP, R, N, D,

• two gearshift combinations which areregistered as intermediate positions(P-R, R-N-D),

• ten gearshift combinations which arediagnosed as being faulty.

SSP 228/095

Four HallSensors(A, B, C, D)

Selector Shaft

Magnetic Gate

70

Control

Gearshift Combinations

Example:

The selector lever is located in selectorlever position “N.” If Hall sensor “C”for example fails, gearshift combination“0 0 0 1” will be implemented.The Transmission Control Module J217can no longer identify selector leverposition “N.” It recognizes the gearshiftcombination as being faulty and initiatesthe appropriate substitute program.

If Hall sensor “D” fails, itwill no longer be possible tostart the engine.

The Transmission Control Module J217requires the information on selector leverposition for the following functions:

• Starter inhibitor control• Backup light control• Park/Neutral interlock control• Information on the vehicle operating

state (forward/reverse/neutral) forclutch control

• Lock ratio when reversing

Different faults in Multi-FunctionTransmission Range Switch F125manifest themselves very differently.Pulling away may not be permitted incertain circumstances.


For a table of gearshift combinations, please refer to the Repair Manual!

srosneSllaHA B C D

noitisoPreveLrotceleS snoitanibmoCtfihsraeGP 0 1 0 1

R-PneewteB 0 1 0 0R 0 1 1 0

N-RneewteB 0 0 1 0N 0 0 1 1

D-NneewteB 0 0 1 0D 1 0 1 0

tluaF 0 0 0 0tluaF 0 0 0 1tluaF 0 1 1 1tluaF 1 0 0 0tluaF 1 0 0 1tluaF 1 0 1 1tluaF 1 1 0 0tluaF 1 1 0 1tluaF 1 1 1 0tluaF 1 1 1 1

71

Control

Transmission Fluid Temperature

Sensor G93

Transmission Fluid Temperature SenderG93 is integrated into the electronics ofthe Transmission Control Module J217.It records the temperature of theTransmission Control Module J217aluminum mounting which is a closeapproximation of the transmissionoil temperature.

Transmission oil temperature influencesboth clutch control and transmission inputspeed control. Therefore, it plays animportant role in the control andadaptation functions.

If Transmission Fluid Temperature SenderG93 fails, the engine temperature is usedto calculate a substitute value. Adaptationfunctions and certain control functionsare deactivated.

Fault indication: inverted


To protect the component parts of thetransmission, engine performance isreduced if the transmission oil temperatureexceeds approximately 293°F (145°C).

If the transmission oil temperaturecontinues to increase, engine performanceis reduced more and more (if necessary,until the engine is running at idling speed).


“Brake Actuated” Signal

The “Brake actuated” signal is required forthe following functions:

• For the function of the gear selectorlever shift lock

• For slip control• For the dynamic control program (DCP)

There is no direct interface to the VacuumVent Valve, Brake F47. The “Brake actuated”signal is provided by the Motronic EngineControl Module J220 across the CAN bus.

SSP 228/107

Motronic Engine Control Module J220

Shift Lock Solenoid N110 inthe Selector Lever BracketCombined Brake

Light Switch F andVacuum Vent Valve,Brake F47

CAN

100 %0

5.0

20 % 40 % 60 % 80 %

72

Control

SSP 228/106

KickdownRange

AcceleratorPedal Limit Stop

MechanicalFull-Throttle Stop

Driver Torque Input

Sig

nal V

olta

ge in

V

Accelerator Pedal Travel

Sender -2- forAccelerator PedalPosition G185

Sender -1- forAcceleratorPedal PositionG79

“Kickdown” Information

A separate switch is not used for thekickdown information.

A spring-loaded pressure element locatedon the accelerator pedal module creates a“point of resistance” conveying a“kickdown feel” to the driver.

When the driver activates the kickdownfunction, the full-throttle voltage value ofSenders -1- and -2- for Accelerator Pedal

Position G79 and G185 in the acceleratorpedal module is exceeded. When a definedvoltage value corresponding to thekickdown point is exceeded, the MotronicEngine Control Module J220 sendskickdown information to the TransmissionControl Module J217 across theCAN bus.

73

Control

TransmissionControl Module J217

SSP 228/108

CAN

Motronic EngineControl Module J220

Accelerator Pedal Module(Contains Sender -1- for AcceleratorPedal Position G79 and Sender -2- forAccelerator Pedal Position G185)

In automatic mode, the most sporty controlcharacteristic for maximum acceleration isselected when the kickdown functionis activated.

The kickdown function does not have to becontinuously activated. After the kickdownfunction has been activated once, theaccelerator pedal need only be held in thefull-throttle position.

If the accelerator pedal moduleis replaced, the kickdown shiftpoint must be calibrated usingthe Diagnosis, Testing andInformation System VAS 5051(refer to Repair Manual).

+ -

P

R N D

Tiptronic Switch F189

Tiptronic Switch F189 is integrated onthe printed circuit board of the gear changemechanism. It has three Hall sensors whichare actuated by a magnet located onthe shutter.

A - Sensor for downshift

B - Sensor for Tiptronic recognition

C - Sensor for upshift

Seven LEDs are located on the printedcircuit board: one for each selector leverposition, one for the “Brake actuated”symbol, and one each for the + and –symbols on the Tiptronic gate.

Four Hall Sensors for Selector Lever Position

SSP 228/079

Each selector lever position LED iscontrolled by a separate Hall sensor.

The switches of Tiptronic Switch F189apply ground (low signal) to theTransmission Control Module J217 whenactuated. If a fault occurs, the Tiptronicfunction is disabled.

Fault indication: inverted

LED

Tiptronic SwitchF189 with ThreeHall Sensors (C, B, A)

Selector Lever Gate

Printed Circuit Boardfor Selector Lever Gate

Solenoid forHall Sensors

Control

74

Control

75

CAN Information Exchange on

multitronic®

In the multitronic® information isexchanged between the TransmissionControl Module J217 and the networkedcontrol modules, apart from only a fewinterfaces, across the drivetrain CAN bus.

The system overview shows informationwhich is supplied by the TransmissionControl Module J217 across the CAN busand received and used by the networkedcontrol modules.

Information Sent bythe Transmission ControlModule J217.

Information Received andEvaluated by the TransmissionControl Module J217.

Driv

etra

in C

AN

Bus

Hig

h

Driv

etra

in C

AN

Bus

Low

Transmission Control Module J217

Specified Engine Torque

Specified Idling Speed

Enable Adaptation —Idling Speed Charge Regulation

Overrun Shut-Off Support

Clutch Protection

Clutch Status

Clutch Torque

Gearshift Operation Active/Inactive

Compressor Switch Off

Selector Lever Position/Drive Position

Vehicle Road Speed

Shift Indicator

Currently Engaged Gear orTarget Gear

Coding in the Motronic EngineControl Module J220

Emergency Running Program(Information on Self-Diagnosis)

On-Board Diagnosis Status

Motronic Engine

Control Module J220

Engine Speed

Specified Idling Speed

Actual Engine Torque

Coolant Temperature

Kickdown Information

Accelerator Pedal Position

Brake Light Switch

Vacuum Vent Valve, Brake

Intake Air Temperature

CCS Status

CCS Specified Road Speed

Altitude Information

Air Conditioner Compressor Status

Emergency Running Program(Information on Self-Diagnosis)

ABS Control Module with

EDL/ASR/ESP J104

ASR Request

EBC Request

ABS Application

EDL Intervention

ESP Intervention

Wheel Speed, Front Left

Wheel Speed, Front Right

Wheel Speed, Rear Left

Wheel Speed, Rear Right

Control

Auxiliary Signals/Interface

The multitronic® provides in addition thefollowing interfaces for informationexchange by CAN bus:

Pin 15 Signal for engine speed

Pin 6 Signal for shift indicator

Pin 5 Signal for road speed

Pin 2 Diagnosis andprogramming interface

Pin 13 Signal for Tiptronic (recognition)

Pin 12 Signal for Tiptronic (downshift)

Pin 14 Signal for Tiptronic (upshift)

Signal for Engine Speed

Engine speed is a key parameter for themultitronic®. To increase the reliabilityof the multitronic®, the information onengine speed is transmitted to theTransmission Control Module J217 by aseparate interface and in addition(redundantly) across the CAN bus (see“Functional Diagram,” page 80).

In the event of faults or if the separate“engine speed signal” interface fails, theinformation on engine speed is adopted bythe CAN bus as a substitute value.

In the event of faults at the “engine speedsignal” interface, the micro-slip controlfunction is deactivated.

76

77

Control

Signal for Shift Indicator

The signal for shift indicator is asquare-wave signal generated by theTransmission Control Module J217 with a20-millisecond constant high level andvariable low level.

Each selector lever position or each“gear” in the Tiptronic function is assignedto a defined low-level duration.

The selector lever position indicator or theshift indicator in the instrument clusterrecognizes by the low-level duration whatselector lever position or what gear isselected and indicates this accordingly.

SSP 228/118Selector Lever Position D

Signal for Shift Indicator on multitronic® — P, R, N, DTrigger Line

Test InstrumentsDSO

Auto Mode

50 ms/Division

T SelectorLeverPosition P

Selector Lever Position R Selector Lever Position N

5 V

/Div

isio

n

78

Control

To simplify the representation, the signalsfrom all six gears for the Tiptronic functionare shown combined in a single diagram.

Signal for Shift Indicator on Tiptronic —

1st, 2nd, 3rd, 4th, 5th and 6th Gear

SSP 228/117

Trigger Line

Test InstrumentsDSO

Auto Mode

50 ms/Division

T

1st 2nd 3rd 4th 5th 6th

Gear5 V

/Div

isio

n

79

Control

Signal for Road Speed

The signal for road speed is a square-wavesignal generated by the TransmissionControl Module J217. The duty cycle isapproximately 50% and the frequencychanges synchronous to road speed.

Eight signals are generated per wheelrevolution and relayed to the instrumentcluster through a separate interface.

The signal is used here for speedometeroperation and is passed on to thenetworked control modules/systems(e.g. engine, air conditioning system, audiosystem, etc.) by the instrument cluster.

1

7

2 3 4 5 6

V

Z

+-

U

U

U

YXW

31 31

ϑ

PRND

+

–

P P

80

Control

Functional Diagram

SSP 228/030Color Codes

= Input Signal

= Output Signal

= Positive

= Ground

= Bidirectional

= Drivetrain CAN Bus

multitronic®

Terminal 15

J226

Terminal 30

N110

SS

F

N88 N216 N215

N182 G195 G196 F125

J217G194 G193 G93

F189

81

Control

Connections and Auxiliary Signals

U To Tiptronic Steering Wheel (Option)V From Terminal 58dW To the Backup LightsX From Ignition Switch Terminal 50Y To Starter Terminal 50Z To the Brake Lights

1 Drivetrain CAN Bus Low2 Drivetrain CAN Bus High3 Signal for Shift Indicator4 Signal for Road Speed5 Signal for Engine Speed6 K-Diagnostic Connection7 Installed in the Hydraulic

Control Module

Because there are onlya few interfaces to theTransmission Control ModuleJ217, the multitronic®does without a separatewiring harness. The wiringis integrated in theengine harness.

Components

F Brake Light SwitchF125 Multi-Function Transmission Range

SwitchF189 Tiptronic Switch

G93 Transmission Fluid TemperatureSensor

G182 Sensor for Transmission RPMG193 Automatic Transmission Sender -1-

for Hydraulic PressureG194 Automatic Transmission Sender -2-

for Hydraulic PressureG195 Sender for Transmission Output

RPMG196 Sender -2- for Transmission

Output RPM

J217 Transmission Control ModuleJ226 Park/Neutral Position Relay

N88 Solenoid Valve 1N110 Shift Lock SolenoidN215 Pressure Control Valve -1-

for Automatic TransmissionN216 Pressure Control Valve -2-

for Automatic Transmission

S Fuse

82

Control

Dynamic Control Program

The Transmission Control Module J217 hasa dynamic control program for calculatingthe target transmission input speed.

It is a further development of the dynamicshift program (DSP) already being used inthe CVT.

The object of the dynamic control programis to set the gear ratio so performancematches the driver input as closely aspossible. The driving feel should be likedriving in manual mode.

ResultActual Transmission Input Speed

(and Hence Engine Speed)

Transmission Control

Influencing Factors(e.g. Engine Warmup)

Calculation of Target Transmission Input Speed (Pulley Set 1, Sensor for Transmission RPM G182)

Evaluation of Road Speed andRoad Speed Changes

(Sender for TransmissionOutput RPM G195)

Evaluation of Signals from theAccelerator Pedal Module

Actuation Rate and Position ofAccelerator Pedal

Evaluation of Road Speed andRoad Speed Changes

(Sender for TransmissionOutput RPM G195)

Driver Input

EconomicalSporty

Vertical Section of Route

UphillDownhill

Level

Vehicle Operating State

AccelerationDeceleration

Constant Speed

83

Control

For this purpose the system determinesthe driver's behavior, the vehicle operatingstate and the vertical section of the routeso it can provide the optimum gear ratio inany driving situation.

The Transmission Control Module J217evaluates the actuation rate and angularposition of the accelerator pedal (driverinput), as well as the road speed andvehicle acceleration (vehicle operatingstate), and whether the vehicle is movingup or down a hill or on a level road(vertical section of route).

Using logical combinations of thisinformation, the target level fortransmission input speed is set byvarying the transmission ratio to matchvehicle performance as closely as possibleto driver input. These target levels arerestricted by transmission input rpm limitsand by the performance range parametersfrom most economical to most sporty.They must also account for the verticalsection of the route traveled.

The logical combinations and calculations(control strategy/control philosophy) aredefined by the software and cannotaccount for every eventuality. Therefore,there are still situations in which manualintervention using the Tiptronic functionis called for.

Control strategy varies by vehiclemodel, engine displacement, andcontrol module design.

Vertical Section of Route

UphillDownhill

Level

Vehicle Operating State

AccelerationDeceleration

Constant Speed

Driver Input

EconomicalSporty

84

Control

Dynamic Control Program

Control Strategy

The following examples show controlstrategy during typical driving situations.

Illustration SSP 228/119 shows the speedcharacteristics when accelerating at fullthrottle with the kickdown activated.

By activating the kickdown, the driversignals to the Transmission ControlModule J217 that maximum accelerationis required.

To achieve this, the engine's maximumpower output must be provided quickly.For this purpose engine speed is adjustedfor maximum performance and maintaineduntil the accelerator pedal angle is reduced.

Although the driver will be required toadjust to this unusual behavior, it makesit possible for the vehicle to acceleratewith the maximum possible dynamism.In addition, the vehicle's top speed as afunction of rolling resistance is kept at themaximum possible value.

The fact that the engine speed increasesquickly but the engine does not accelerateto the same extent results in what isknown as the “rubber band effect” or whatfeels like a “slipping clutch.” This effect isalleviated by “intercepting” the increase inengine speed shortly before maximumengine speed is attained.

Kickdown

Acceleration

SSP 228/119

Time

100

80

60

40

20

0

6000

5000

4000

3000

2000

1000

124 (200)

93 (150)

62 (100)

31 (50)

0 (0)

Engine SpeedRPM

Accelerator PedalPosition in%

Road Speedin mph (km/h)

85

Control

To contain this effect, “normal”accelerationat full throttle (without kickdown), as wellas acceleration with lesser acceleratorpedal angles, are characterized by thespeed characteristics shown in illustrationsSSP 228/124 and SSP 228/122.

The “engine speed tracking” function isused for this purpose. Engine speed isregulated depending on the position andactuation rate of the accelerator pedal so

Full Throttle

Acceleration

engine speed increases directlyproportional to road speed.

This control strategy simulates theperformance of multi-step transmissionsand closely matches the driving feel whichthe driver is accustomed to. In keeping withdriving style, the engine rpm level is high(sporty) at large accelerator pedal anglesand low (economical) at small acceleratorpedal angles.

SSP 228/122

Part Throttle

Acceleration,

Throttle 80%

Open

SSP 228/124

Time

Time

1006000

5000

4000

3000

2000

1000

124 (200)

93 (150)

62 (100)

31 (50)

0 (0)

80

60

40

20

0

100

80

60

40

20

0

6000

5000

4000

3000

2000

1000

124 (200)

93 (150)

62 (100)

31 (50)

0 (0)

Engine SpeedRPM



86

Control

As shown in illustration SSP 228/123,quick changes in accelerator pedalposition are converted to instantaneouschanges in engine speed in order to meetthe driver's demands for performanceor acceleration.

If the driver adopts an economical drivingstyle, as characterized by small acceleratorpedal angles and a slow rate of openingof the throttle, then road speed is increasedat the lowest engine rpm levels (seeillustration SSP 228/121).

Engine Speed

Response to

Quick Changes

in Accelerator

Pedal Angle

Time

Time

SSP 228/123

SSP 228/121

Acceleration in

an Economical

Driving Mode

100

80

60

40

20

0

6000

5000

4000

3000

2000

1000

124 (200)

93 (150)

62 (100)

31 (50)

0 (0)

100

80

60

40

20

0

6000

5000

4000

3000

2000

1000

124 (200)

93 (150)

62 (100)

31 (50)

0 (0)

Engine SpeedRPM



87

Control

In general, the system responds to areduction in the accelerator pedal angle byreducing the engine rpm level as shown inillustrations SSP 228/120 and SSP 228/123.

If the accelerator is suddenly released,particularly in a sporty driving mode, theengine speed is “held” at a higher levelfor longer.

Acceleration

with Reduced

Accelerator

Pedal Angle

By increasing the braking effect of theengine (high overrun speed), this controlstrategy helps to brake the vehicle andincreases engine dynamism for instantaccelerator response.

In addition, unnecessary transmission ratioadjustments are suppressed.

SSP 228/120

Time

Engine SpeedRPM



100

80

60

40

20

0

6000

5000

4000

3000

2000

1000

124 (200)

93 (150)

62 (100)

31 (50)

0 (0)

88

Control

Uphill Grade

Higher power demand may be due to anuphill grade or a trailer.

In this case, the engine speed andoutput level must be increased through ashorter ratio without the driver constantlyhaving to open the throttle more as shownin illustration SSP 228/091.

In practice the driver will perceive thiscontrol strategy, known as “loadcompensation,” as a comfort increase.

Motion Resistance

“Power in relation to load” is calculatedin order to detect motion resistance(uphill grade, downhill grade, vehicleoperation with trailer in tow).

It indicates whether power demand ishigher or lower compared to the rollingresistance during vehicle operation on alevel surface (unladen).

PEngine load = Power in relation to load

Pmot = Actual engine output

Pa = Acceleration work

PFW = Power in relation tomotion resistance

Increase in Engine Speed on a Uphill Grade

SSP 228/091

Eng

ine

Spe

ed

Road Speed

Increase inEngine Speed on a5% Uphill Grade

Characteristicwithout Grade

15%Grade

5%Grade

PEngine load = Pmot - Pa - PFW

89

Control

Increase in Engine Speed when Driving Downhill

Driving Downhill

On a downhill grade the situation is slightlydifferent. If the driver wants to be assistedby engine brake effect when drivingdownhill, he must indicate this by pressingthe brake pedal (signal from combinedBrake Light Switch F and Vacuum VentValve, Brake F47).

If the engine is in the overrun phaseand road speed increases even thoughthe brake pedal is pressed, thetransmission ratio is adjusted towardsthe starting torque ratio and with itthe engine braking force is increased.

If the brake pedal is pressed several times(without reduction in road speed), theTransmission Control Module J217gradually adjusts the transmission ratiotowards the starting torque ratio (seeillustration SSP 228/097). Thus the driverhas a great deal of control over the intensityof the engine brake effect.

If the downhill slope decreases, thetransmission ratio is again adjustedtowards the end torque multipliction ratio(overdrive) and the vehicle's road speedincreases slightly.

If the driver enters a downhillgrade pressing the brake pedal(and holds the brake pedaldown), the “downhill function”as described will not be activeinitially. If the road speed is keptalmost constant in this case byapplying the brake, themultitronic® will be unable torecognize the driver's intentionsand therefore cannot assist thedriver by increasing the enginebrake effect. However, if thevehicle exceeds a defined rateof acceleration, the “downhillfunction” will be activatedautomatically.

Engine braking force can becontrolled individually by usingthe Tiptronic function.

SSP 228/097

Press Brake Twice —Engine SpeedIncreases Further,Higher Utilization ofEngine Brake Force

Time

Press BrakeOnce —Engine SpeedIncreases,Engine BrakeEffect Increases

Eng

ine

Spe

ed

90

Control

Driving with Cruise Control

System (CCS)

In overrun mode, the engine brake effect isinsufficient when driving downhill with thecruise control system (CCS) turned onbecause the transmission ratio is often low.

In this case, the engine brake effect isincreased by raising the target transmissioninput speed (transmission control isadjusted towards the starting torque ratio.)

The CCS set road speed is always slightlyhigher than the actual road speed. This isdue to the control tolerance of the CCS andthe safety requirement that the enginemust be in overrun mode.

A maximum overrun speed whichserves as a limit value for transmissioninput speed control is stored in theTransmission Control Module J217.When the maximum overrun speed isreached, the transmission ratio is notadjusted further towards the startingtorque ratio and therefore is limited.

If the engine brake effect is insufficient atmaximum overrun speed, the vehicle'sroad speed increases and the driver has toapply the brakes.

The Tiptronic Function

As mentioned previously, six “gears” canbe selected manually in Tiptronic mode.In this mode, defined transmission ratiosare set and “gears” are simulated(see also page 4).

The performance and shift strategies areidentical to the multi-step transmission withTiptronic (mandatory upshift or mandatorydownshift).

If the Tiptronic function is selected whiledriving, transmission output is stabilized atits current ratio for a seamless transition.The first driver action to select a “gear”will result in a shortened step up or downto one of the six preset Tiptronic ratios.The defined transmission ratios are thenset step by step by shifting up or down.

Reason:

Because the transmission ratio could bebetween two “gears” at the point ofchange-over to Tiptronic mode, animmediate change into a defined ratiocould lead an abrupt change in roadspeed depending on the difference inratio to the next “gear.”

91

Service

Towing

To make towing possible, design measureshave been implemented in the Variator (see“The Variator,” page 27 for details).

When towing a vehicle with multitronic®,the following conditions must be fulfilled:

• The selector lever must inthe “N” position.

• The vehicle's road speed must

not exceed 30 mph (50 km/h).

• Vehicles must not be towed furtherthan 30 miles (50 km).

When towing the vehicle,the oil pump is not driven androtating parts are not lubricated.

Care should therefore betaken in meeting the above-specified conditions since thetransmission may otherwisebe damaged severely.

It is not possible to start thevehicle by towing.

92

Service

Special Tools

The following special tools will be requiredby the service department.

Transmission Lift Hook

T40013

Test Box

V.A.G. 1598/21

Oil Seal Extractor

T40014

SSP 228/125

SSP 228/067

12

34

567

89 10 11 1213 14 15 16 17 1819 20 21 22 23 2425

SSP 228/066

Seal Installer

T40015

93

Service

SSP 228/070

ATF Filler System

VAS 5162

SSP 228/069

Adjustment Plate

3282/30

SSP 228/068

Notes

94

Knowledge Assessment

iii

An on-line Knowledge Assessment (exam) is available for this SSP.

The Knowledge Assessment may or may not be required for Certification.

You can find this Knowledge Assessment at:

www.accessaudi.com

From the accessaudi.com homepage:

Click on the “ACADEMY” Tab –

Click on the “Academy Site” Link –

Click on the ”CRC Certification” Link –

For assistance, please call:

Audi Academy

Learning Management Center Headquarters

1-877-AUDI-LMC (283-4562)

(8:00 a.m. to 8:00 p.m. EST)

Knowledge Assessment

Date post:	07-Nov-2014
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Audi 01J Multitronic CVT

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