Presentation Objective

At the end of this presentation you will be able to:• Describe the benefits of electronically controlled

engines.• Answer basic questions relating to system

components.• Use a multi-meter to perform continuity, Ohms and DC

volts• Understand the functions of Electronic Technician (ET)• Describe the basic concept of Controller Area Network

(CAN) and SAE J1939.

Caterpillar 3000 Series 3054E/3056E

Electronic Control Module (ECM)

Manifold Pressure Sensor

Intake AirTemperature

Sensor

Engine Oil PressureSensor

Engine CoolantTemperature Sensor

Machine Interface Connector

Service Tool Connector

(Industrial Engine)

PrimarySpeed/Timing

Sensor

Bosch VP30Pump

3000 Series Basic Engine Schematic

Service ToolConnector

Intake ManifoldTemperature Sensor

Intake Manifold Pressure

Sensor

Primary Speed/Timing

Sensor

VP30 Electronic Distributor

Pump

36-1 Tooth Crank Gear

A4 E1

ET

PumpECU VLPM

Machine Interface Connector

Engine CoolantTemperature Sensor

Engine Oil Pressure

Sensor

System Components - Wiring Harness• Engine harness connects engine mounted sensors and

actuators to ECM• Traditionally wiring and connectors is highest cause of

reliability problems • Incorporates robust sealed connectors

• Connectors are designed for long service life

• Cable insulation is capable of withstanding temperature and fluid exposure

• Outer covering provides protection from damage due to vibration, heat and general abuse

• Harness routing and connector ‘keying’ is used to prevent incorrect connection of components

Electronically Controlled Fuel Systems

Caterpillar 3000 Series

VP30 Pump

Bosch VP30 Fuel Injection PumpPUMP CONNECTOR

Pump Supply/CAN Link/Engine Speed/Timing/

Fuel Shutoff Connector

Fuel Quantity Solenoid Valve

Pump ECU

Timing Control Solenoid

Secondary Speed/Timing

Sensor

Fuel Temperature Sensor

TRANSFERPUMP

PRESSUREREGULATOR

TIMING ADVANCEMECHANISM

TIMINGSOLENOID

FUEL QUANTITYSOLENOIDVALVE

DELIVERYVALVE

INJECTOR

SPEED TIMINGSENSOR

ELECTRONICALLY CONTROLLED FUEL SYSTEMHIGH PRESSURE STAGE

LIFTPUMP

(PRIMING PUMP)

DISTRIBUTORPLUNGER

ENGINE ECM(A4 CONTROLLER)

PUMP ECU

FUEL RETURNCHECK VALVE

CAMPLATE

ROLLER

RING

ROLLERPLATE

ORIFICE

A4 ECM (3054E/3056E)

One ECM fits all applications

Basic System - Interactions

CATDATALINK

Switches/Pushbuttons

Sensors:Pressure,Temperature,

Speed/Timing

INPUTS

Power Supply12 v or 24 v

5/8 voltssensor supplies and operationComputerHardware

+Software

ECM

CONTROLINPUTS OUTPUTS

Indicator lights

ActuatorsCables/Connectors

Cables/Connectors

Relays

OUTPUTSC.A.N.DATALINK

SERVICE TOOL PUMP TO ECM/FLASH

System Components -ECM Hardware

Analoguevoltage

PWM

PROCESSOR

MEMORY

OUTPUTS

Digital

PWM

COMMUNICATIONSLINKS

INPUTS

Digital

System Components - ECM HardwareECM hardware technology trends

• Size reducing through circuit integration and packaging technology

• I/O (inputs and outputs) increasing - expected to plateau

• Memory capacity increasing - more software, more data logging capacity

• Processing power increasing - more calculations within fixed loop time (typically 25ms)

• Environment becoming harsher - cab to engine bay to on-engine

• Reliability improving through packaging technology and manufacturing process improvements.

• Cost reducing - reduced component costs, optimised design, high volume manufacture

Electronic Control Module: Essential Facts

• High reliability

• External connectors most vulnerable

• No serviceable parts

• Never replace without full diagnostic test

• All warranty returns checked

• No fault warranty returns - no warranty credit

• ECM is the LAST component you should suspect being faulty

Sensor Types

Engine Speed Controls

System Components – Speed ControlsThrottle PositionSensors/Controls

• Cat Machines- Pulse Width Modulation (PWM)- Set Speed Switches

• Industrial Engine, pedal position/operator demand

- Pulse Width Modulation (PWM)

- Contacting, resistive track potentiometer type devices.

• Provide linear voltage output (0.5v to 4.5v)

• Should have idle validation switches on mobile applications for failure detection.

Volta

ge o

/p

Low Idle

High Idle

PWM Throttle Position Sensor• Ground

• +8 Volt supply

• PWM Output

Three wires:

System Components -Throttle Position Sensors

• Pulse Width Modulation (PWM) is an output that is defined by its duty cycle.

• The duty cycle is the relation between the time on to the time off.

• More consistent than a linear sensor type.

• Above 90% and below 10% implies there is an error present.

IDLE(0.9volts)

FULL THROTTLE (4.6volts)

System Components

• Passive Sensors:- Commonly known as magnetic pick-ups- Produce a sinusoidal voltage signal. Signal

conditioning is required in the ECM

• Active Sensor:- Hall effect- Produce a ‘conditioned’ square wave signal- More expensive than passive sensors

Engine Mounted Sensors

On Engine Sensor Wiring

ECM

14 INTAKE MANIFOLD PRESSURE

A

B

C

1

2

1

2

INTAKE MANIFOLD AIR TEMPERATURE

SENSOR COMMON

26 SENSOR VREF +5 VOLTS

34 SENSOR COMMON O VOLTS

15 ENGINE COOLANT TEMPERATURE

32 INTAKE MANIFOLD AIR TEMP

24 ENGINE OIL PRESSURE

49 CRANKSHAFT POSITION -41 CRANKSHAFT POSITION +2

1

CRANKSHAFT POSITION +

CRANKSHAFT POSITION -

ENGINE OIL PRESSURESENSOR

INTAKE MANIFOLDPRESSURE SENSOR

ENGINE COOLANTTEMPERATURE SENSOR

INTAKE MANIFOLDTEMPERATURE SENSOR

SPEED AND TIMING SENSORNO.1

J103 P103

J401 P401

L730

994X731

995

C967L731

E965

P1 J1

33 CRANKSHAFT POSITION SCREEN

ENGINE COOLANT TEMPERATURE

SENSOR COMMON

J100 P100

A

B

C

SENSOR VREF +5V

ENGINE OIL PRESSURE

SENSOR COMMON

J201 P201

SENSOR VREF +5V

INTAKE MANIFOLD PRESSURE

SENSOR COMMON

J200 P200

E966

System ComponentsTemperature Sensors

• Thermistors:

- Semiconductor sensing devices

- Resistance varies with temperature

- Negative Temperature Coefficient (NTC) most common i.e. As temperature increases its resistance decreases

- 40 to 300ºF range

- Passive sensor ⇒ lower cost

Temperature Sensors

• Thermistor

Pin No 2

Pin No 1

Ground

Signal

Temperature Sensors

• 3054E/3056E Applications

- Intake Manifold Temperature Sensor

- Engine Coolant Temperature Sensor

System Components -Temperature Sensors

VoltsOhms(Resistance)

VoltsOhms

5.025,000

5,0000.5

Increasing Temperature

+5 VOLTS REFERENCESUPPLY

ANALOGUE TODIGITAL

CONVERTER

MICROPROCESSOR

R2

0 VOLTS

ECM

Temperature (Passive)Sensor Operation

R1

TEMPERATURESENSOR

System Components -Pressure Sensors

Pressure:

• Active Sensors (i.e. with built in conditioning electronics) provide analogue voltage output with linear and temperature compensation.

• Various working ranges to suit measured parameter e.g.

- 12 to +17 psi (abs) - Atmospheric pressure

0 to 70 psi (abs) - Intake manifold pressure

0 to 115 psi (abs) - Engine oil pressure

abs = absolute (pressure)

Pressure Sensors

Oil Pressure Sensor

Intake ManifoldPressure Sensor

A (5 Volts)

B (Sensor Return)

C (Signal)

Pressure Sensors

Change of Voltage with Pressure.

Out of range4.5

Volts

0.5Out of Range

Pressure

+5 VOLTS REFERENCESUPPLY

ANALOGUE TODIGITAL

CONVERTERMICROPROCESSOR

0 VOLTS

+12V

ECM

Pressure Sensor Circuits

System Components

Other Sensors (Industrial):

• Coolant Level Sensor

System Components

Speed/Timing Sensors• Applications:

- Determine rotational speed and rotational position

• Primary - Crankshaft speed and position

• Secondary - Camshaft/fuel pump speed and position

Primary Speed/Timing Sensor

Speed/Timing Sensor

70 Degrees4 CYL

40 Degrees - 6 Cylinder

Top Dead Center

Rotation

• The 3000 series engines use a 36-1 tooth ring. i.e. the timing ring has space for 36 teeth, and one is missing. The missing tooth allows the ECM to determine the timing of the engine. The wheel is dowelled to index it to the crankshaft.

System Components - Speed Sensors

Iron Core

Teeth

Pole Piece

Passive Speed Sensors Magnet

Coil

Flux Lines

Direction ofmotion

Secondary Speed/Timing Sensor Installation

Cra

nksh

aft

Speed/Timing Sensor

ECM

(6 cylinder Engine)

System Components – Speed/Timing Sensors

Speed/Timing Sensors – failure ModesPrimary sensor

Defaults to SecondarySecondary sensor

Engine stops and will not start

Teeth

System Components -Output Devices

• Typically include:

- Relays

- Lamps

- Gauges (PWM)

System Components - Actuators

Electronically Controlled Fuel Pump

• “Intelligent” rotary pump e.g. Bosch VP30

- Local pump mounted ECU controls pump solenoids to achieve desired fuel delivery and timing.

- Main ECM communicates desired timing and fuelling via CAN communication link

Electronic Service Tools

• Communication Adapter (CA II)

• CAT ET (Electronic Technician)

Electronic Service Tools

CAT ET Service Tool:

• PC based, multi function

- Status Screens

- Diagnostics

- Flash Programming

Electronic TechnicianCAT ET

The first element of STW (Service Technician Workbench)

Common for all future Caterpillar electronic engines

Hardware and software required

Annual subscription

Not compatible with Perkins 1100 Series engines

Communication Adapter GroupET Service Tool

CAT ET (Electronic Technician)Functionality includes:

Fault CodesData recording and graphingEngine Configuration Horsepower, customer operational parameters, P.T.O. cruise, Multi-position switch.

Flash Programming (ECM re-programming)Supports troubleshooting processDisplays parameters, temperature, speed, pressure etc.

Electronically Controlled EnginesARE ABLE TO

• Indicate active faults, logged faults and events

• Identify sensor and actuator short and open circuits

CANNOT

• Troubleshoot themselves

• Identify inaccurate sensor readings

Application Wiring

Warning Lamps

J20P20

IN LINE FUSE (F3)

J1P1MIC CONNECTOR ECM CONNECTOR

Stop Lamp

Warning Lamp

2312

2312

Data Links

Cat Data Link (CDL)

Controller Area Network (CAN)

(Two CAN data links on 3054/56E)

Example of CAN wiring

MACHINE INTERFACE CONNECTOR

Ohm TERMINATINGRESISTOR

120 Ohm TERMINATINGRESISTOR

5261

GEARBOXECM

Address 3

INSTRUMENT PANEL

Address 23

ENGINEECM

Address 0

HAND HELDSERVICE TOOL

Address 249 DATA BUS

NODE

NODE

The CAN shield not connected to ECM

Controller Area Networks (CAN)

Introduction:

• CAN is the communication network between intelligent electronic devices used on an application.

• Ground based equipment use a version of CAN that conforms to an international standard known as J1939

• Application control, monitoring and diagnostics is possible using J1939.

Controller Area Networks (CAN)

Advantages:

• Uses less wiring, lower weight, lower cost, etc.

• Uses fewer connections, more reliable.

• Easier to install.

• Improved quality of signal.

• Transmission of huge amounts of data.

3054E/3056E CAN Data Link Usage

CAN J1939

• Flash Programming

CAN Proprietary Data Link

• ECM to Pump ECU communication

CAN - J1939Examples of CAN Data link Uses:

• ECM to Engine Fuel Pump: Transmits engine power requirements to pump ECU

• Transmission to Engine: Tells the engine what gear is currently selected

• Engine to Machine: Broadcasting of engine parameters (e.g. engine speed, oil pressure, coolant temp.)

Flash Programming

Bus Fault Finding - (CAN)

Ensure CAN high and low wired connected correctly

Check shield

Ensure 120Ω resistors wired correctly

Ensure that no short circuits are present

Check for possible electrical interference