- handbook for the installer -

02.2001

M.T.M. s.r.l.

Via La Morra, 112062 - Cherasco (Cn) - ItalyTel. ++39 0172 48681Fax ++39 0172 488237

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1. PRESENTATION1.1. GENERAL FEATURES1.2. GENERAL LAYOUT OF THE EQUIPMENT1.3. DETAILED DESCRIPTION OF THE SYSTEM COMPONENTS

1.3.1. ECU AND CHANGEOVER SWITCH

1.3.1.1. Changeover function for injection cars1.3.1.2. Changing over again in out-of-the revs threshold condition1.3.1.3. Control function of the gas quantity1.3.1.4. Function of injectors emulation and fuels overlapping1.3.1.5. Emulating function of the configurable lambda oxygen sensor signal1.3.1.6. Function of the memory management and of the signal cutting relay contact 1.3.1.7. Level gauge 1.3.1.8. Dialogue with the Diagnostic Box1.3.1.9. Dialogue with the BRC Portable Computer1.3.1.10. Double possibility for setting and starting operations1.3.1.11. Self-configuration of the system to the vehicle signals 1.3.1.12. Self-adapting of the system1.3.1.13. Check-up of the system 1.3.1.14. Troubleshooting

1.3.2. DIAGNOSTIC-BOX

1.3.3. INTERFACE PROGRAMME ON COMPUTER

1.3.4. HARNESS

1.3.5. GAS FLOW CONTROL ACTUATOR

1.3.6. REDUCER

1.3.7. MIXER

1.4. ADVANTAGES OF THE JUST SYSTEM

2. INSTALLATION OF THE SYSTEM2.1. PRELIMINARY OPERATIONS2.2. ECU FIXING2.3. ECU CONNECTION

2.3.1. 5-POLE DIN CONNECTOR FOR DIAGNOSTIC BOX

2.3.2. CONNECTION TO THE BRC PORTABLE COMPUTER

2.3.3. 24-POLE HARNESS

2.3.3.1. 10-way connector for changeover switch2.3.3.2. 4-way connector for the STEP control actuator 2.3.3.3. Connection of the gas level sensor2.3.3.4. Startend Connector2.3.3.5. Reset Connector2.3.3.6. “A” Sheath2.3.3.7. “B” Sheath2.3.3.8. “C” Sheath2.3.3.9. “D” Sheath2.3.3.10. “E” Sheath

TABLE OF CONTENTS

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2.4. ASSEMBLY OF THE CHANGEOVER SWITCH2.5. ASSEMBLY OF THE GAS LEVEL GAUGE2.6. ASSEMBLY OF THE GAS FLOW CONTROL ACTUATOR2.7. ASSEMBLY OF THE MIXER2.8. ASSEMBLY OF THE REDUCER

3. CONFIGURATION AND SETTING OF THE SYSTEM FROM THECHANGEOVER SWITCH

3.1. THE DIAGNOSTIC BOX3.1.1. VISUALISATION OF THE SIGNALS ON THE LED-BARS

3.1.2. NUMERIC VISUALISATIONS

3.2. PRELIMINARY CONTROLS3.3. CONFIGURATION AND SETTING DOMAINS

3.3.1. LED READOUT ON THE CHANGEOVER SWITCH

3.4. FIRST ACQUISITION AND AUTOMATIC SELF-CONFIGURATION3.4.1. ACQUISITION AND SELF-CONFIGURATION OF THE TPS SIGNAL

3.4.2. ACQUISITION AND SELF-CONFIGURATION OF THE R.P.M. SIGNAL

3.4.3. ACQUISITION AND SELF-CONFIGURATION OF THE LAMBDA OXYGEN SENSOR SIGNAL

3.4.4. ACQUISITION OF THE RESET POSITION OF THE STEP ACTUATOR

3.5. ADDITIONAL MANUAL SETTING AND PARAMETERS SETUP3.5.1. ACTIONS TO BE TAKEN IN THE ADDITIONAL MANUAL SETTING DOMAINS

3.5.2. LOW LEVEL GAUGE THRESHOLD SETTING (EMPTY TANK) 3.5.3. 4/4 THRESHOLD OF THE LEVEL GAUGE (80% FILLING)3.5.4. CHANGING OVER THRESHOLD

3.5.5. NP - NC1/NC2 RELAY CONFIGURATION

3.5.6. FUELS OVERLAPPING TIME

3.5.7. ANALOGIC - ON/OFF TPS SETTING UP

3.5.8. PARAMETERS SET-UP

3.6. DUTY CYCLE VISUALISA TION AND MODIFICATION OF THELAMBDA OXYGEN SENSOR EMULATED SIGNAL

3.7. VISUALISATION AND MODIFICATION OF THE STEP RESET POSITION3.8. SELF-ADAPTING3.9. SYSTEM DIAGNOSTIC

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APPENDICES"A"APPENDIX - DICTIONAR Y OF WORDS AND DEFINITIONS"B"APPENDIX - MAIN TROUBLES, POSSIBLE CAUSES, SOLUTIONS"C"APPENDIX - REFERENCE CODES

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1.1. GENERAL FEATURES

The Just system, destined tofeed automot ive explos ionengines on gas (CNG or LPG), isthe result of a long experienceworked out by BRC Co. in its ownfield.

Indeed, this system is due to asynthesis of the best features ofthe lambda gas control systems,opportunely integrated by innova-tive functions and definitely in thelead in the traditional gas equip-ment field, thanks to the self-con-figuration and the self-adapting.

The system core consists of amicrocontroller with a very high

performance/price ratio and withreally considerable potentials,able to manage manifold func-tions by optimising times, versa-t i l i ty and effect iveness of theECU interventions.

The long and carefu l roadsetup, with vehicles of severaltypes and of different characteris-tics and perfomances, highlightedthe remarkable potential of thesystem, as well as the setup easeand the possibility to optimise thecar working.

The resul ts at ta ined in theapproval emission tests of theproduct are ev idence of theexceptional quality of the mixturecontrol system.

The approval tests from thepoint o f v iew of theElectromagnetic Compatibi l i ty(EMC), successfully passed bythe system, h igh l ighted i tsstrength to the electromagnetictroubles and confirmed the validi-ty of the planning and realisationstrategies.

1.2. GENERAL LAYOUTOF THE EQUIPMENT

The Just system is applied onany type of engine converted togas with a traditional BRC equip-ment (LPG or CNG indifferent-ly).

The ECU, with a microcon-troller, manages the control of thewhole gas equipment and adjuststhe fue l quant i ty in feedbackthrough the STEP actuator inorder to obtain an optimum mix-ture, both in respect of pollutionand consumptions, and of drive-abi l i ty, aside from the outsidecondit ions (temperature, etc.)and the fuel composition.

The system setting and start-ing, widely based on self-config-uration and self-adapting proce-dures, present two poss ib le“approaches”:

- complete configuration andstar t ing of the system sole lybased on the changeover switchand on the BRC Diagnostic Box;

1. PRESENTATION

Fig. 1General layout ofthe equipment

BRCPRESSURE REDUCER

LPG Solenoid Valve

Multivalve LPGTank

Refuelling point

(possible)BRC

portable computer

DiagnosticBox

JUSTElectronic Control Unit (ECU)

Changeover switch

Injectorsmodule

Vehicle original

injection ECU

Engine

Lambda oxygen sensor

TPS

Injectors

Petrol tank

Exhaust gas

Throttle body

MIXER

STEP ACTUATOR

Catalytic converter

Lambda oxygen sensor

Rear sol.valveLevel gauge

STEP control

Ignition impulses

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- possibility of carrying out asetup through the system manag-ing interface from computer, for adialogue in real t ime with theECU, by allowing a careful con-trol of the equipment working, aswell as a comfortable, close andspecific setting.

The fig. 1 represents the totallayout of the equipment, in partic-ular:

- the Just electronic controlunit (ECU);

- the changeover switch withthe level gauge;

- the connection with the BRCDiagnostic Box;

- the possible connection tothe BRC Portable Computer;

- the STEP gas flow controlactuator;

- the reducer;- the mixer;- the lambda oxygen sensor.Such a layout is only aimed at

g iv ing an overa l l v iew of theequipment.

A lot of details can vary from avehicle to another and, for thatreason, please refer to the specif-ic diagrams of each model.

The fig. 2 represents in detailthe main electronic and electriccomponents of the system, whichcomprehends:

- the ECU;- the changeover switch;- the STEP gas flow control

actuator;- the harness.

1.3. DETAILED DESCRIP-TION OF THE SYSTEMCOMPONENTS

1.3.1. ECU AND CHANGEOVER

SWITCH

The Just ECU can be consid-ered the operat ive unit of thewhole gas equipment.

Through the special harnessrequisite to easily reach the cardifferent parts concerned, andthanks to the in let and out letstages opportunely dimensionednot to alter or absolutely damagethe car normal running on petrolin time, it is able to manage thewhole Just system in the courseof its duty.

1.3.1.1. Changeover functionfor injection cars

The changeover switch con-sists the Just system more imme-diate in ter face wi th the user :through it the ECU supplies theinstructions necessary for the dri-ver.

The Just changeover switch,even though it follows the sameline of the other BRC products asfor the standard functions, pre-sents manifold additional func-tions reserved to the self-acquisi-

tion, setting and diagnostic pro-cedures of the system.

Together with the changeoverswitch a sticker is supplied for itsupright positioning (it is sufficientto remove and rep lace thealready mounted one).

The changeover switch (fig. 3)has three positions allowing threetypes of working.

a) Working on "forced petrol".With the changeover switch

button pressed lef twards, thetwo-coloured rectangular LEDturns red, the injectors are work-ing, the gas solenoid valves areclosed, the gas flow control sys-tem is off.

The car regular ly runs onpetrol, as if there weren’t the gasequipment.

b) Work ing wi th petro l -gasautomatic changing over.

With the changeover switchbutton in the central position andthe ign i t ion key on, the two-co loured LED is b l ink ing red(central position without revs);the car s tar ts on petro l ( two-coloured LED is fixed red) andthen i t automatical ly changesover to gas (two-coloured LED isfixed green), according to a suit-

Fig. 2View of the ele-ments making upthe unit

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able changing over s t ra tegybased on the r.p.m. and on theTPS s ignal . The threshold toenable the changing over isadjustable via software (Chapters3 and 4). An orange shade of thetwo-coloured LED marks out thatthe changing over enabl ingthreshold has been get over withthe car still running on petrol (insuch conditions, a decelerationdetermines the changing over togas).

The automat ic changingover to gas is inhibited for ashort interval just after the carignition (approx. 5 seconds).

Evidently, whi le running ongas, the injectors are disconnect-ed, because the outside cuttingdevice and the possible emula-tion of the injectors are enabled,the gas solenoid valves are open,the gas flow control actuator iscontrolled and possible furtherdevices, if any, are enabled.

This is the recommendedposition for running on gas.

The system automatical lychanges over to petrol again incase of failed starting or acci -dental stopping (safety car)and such a condition is pointedout by a shifting lighting of aLED at a time from the left sideto the right side and back.

In a similar way , it automati -cally changes over to petrolagain ( two-co loured LED isf ixed red) in case of r .p .m.above the threshold with a sub -sequent automatic changing

over to gas when returning tonormal conditions (par. 1.3.1.2).

c) Working on "forced gas".With the button pressed right-

wards and the ignition key on, thepriming is immediately carried out(timed opening of the gas sole-noid valve, to allow the car start-ing).

The two-coloured LED turnsgreen (blinking without revs andfixed in case of priming or enginerunning) and the car runs exclu-sively on gas.

In this case too the systemautomatically changes over topetro l again in case of fa i ledstarting or accidental stopping(safety car) and of r.p.m. abovethe threshold.

This function is to be con -sidered as an emergency solu -tion, to be used solely in caseof failure of the petrol feedingequipment and with the great -est care to prevent the pumpfrom running dry , wi th theempty tank.

It is consequently advisableto always keep a petrol quantityof 1/3 or 1/4 of the tank and torenew it rather often so that itdoesn’t alter.

1.3.1.2. Changing over again inout-of-the revs threshold con -dition

In case the engine is in out-of-the revs threshold condition,while running on gas, the sys -tem automat ica l ly changesover again to petrol , allowing touse the revs limiting strategiesimplemented in the petrol injec-tion ECU.

When returning to accept -able working conditions, theECU automatically enables thechanging over to gas again.The changing over to gas iscarried out as soon as the suit -able conditions take place (see

par. 1.3.1.1).Both the entry threshold in

out-of-the revs threshold condi-t ion and the one returning toacceptable working condit ionsare conf igurable v ia sof twarefrom the interface programme oncomputer.

1.3.1.3. Control function of thegas quantity

The system acts as a “closedloop”, by correcting the air/gasmixture s t rength in rea l t imeaccording to the information com-ing from the lambda oxygen sen-sor. As everybody knows, thisone produces a voltage signaldepending on the oxygen presentin the exhaust gas and thereforesupplies an indirect measure ofthe mixture strength (lean, stoi-chiometr ic, r ich), al lowing theECU to act on the gas flow con-trol actuator, through a suitablepower stage.

The correction of the mixturestrength in real time is carriedout both according to the infor-mation coming from the lambdaoxygen sensor, and through theanalysis of the different drivingcondi t ions of the car (mapsbased on the engine load).

The Just electronic card hasbeen exclusively conceived formanaging the BRC STEPpatented actuator involved inthe system i tsel f and is notcompatible with different actu -ators.

1.3.1.4. Function of injectorsemulation and fuels overlap -ping

The Just ECU doesn’t haveeither the injectors cutting func-tion inside it or the injectors emu-lator.

It is therefore necessary toinstall an outside module (emula-tor, disconnector, etc.), available

Fig. 3Just Changeover Switch

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in different versions according tothe inject ion type and the carspecific requirements.

By connect ing the outs ideemulator power-supply to theWhite/Green wire of the Just ECU(par. 2.3.3.4), the fuels overlap-ping function is obtained.

The fuels overlapping time isprogrammable v ia sof tware(Chapters 3 and 4).

1.3.1.5. Emulating function ofthe configurable lambda oxy -gen sensor signal

The Just ECU incorporates aconfigurable lambda oxygen sen-sor signal emulator which canperform functions of both fixedemulation and emulation at vari-able richness.

The choice is associated tothe set t ing-up of the NP –NC1/NC2 re lay contact (par.1.3.1.6), that is to say the emula -tion at a variable richness isassociated to the NP setting-up, whereas the fixed emula -t ion is assoc ia ted to theNC1/NC2 setting-up.

In case of emulation of thelambda oxygen sensor signal at avariable richness, it is possible toprogramme the duty cycle of thelambda signal emulated with a1% resolution (Chapters 3 and4).

1.3.1.6. Function of the memorymanagement and of the signalcutting relay contact

The White and White/Orangewires can have a double function,conf igurable v ia sof tware(Chapters 3 and 4):

- memory resetting function ofthe petrol injection ECU (NP);

- relay contact function for cut-ting signal (NC1/NC2).

The NP function of the Whiteand White/Orange wires is usual-ly used only on cars where it is

necessary to reset the memory ofthe petrol injection ECU.

For using the NC1/NC2 func-tion (corresponding to the relaycontact for cutting signal), pleaserefer to the specific diagrams ofeach car.

1.3.1.7. Level gauge

Inside the change over switchthere is a level gauge consistingof a LED bar with four GREENLEDs. The low fuel warning isobtained through the first LEDblinking.

Its working can be obtained byconnecting to the ECU one of theavailable BRC level sensors, bothof the Hall effect type and of theresistive type (see the Chapter 2for ins ta l la t ion and the “C”Appendix for the re ferencecodes).

The level gauge is preset, butthe indication can be improved orcorrected via software (Chapters3 and 4).

1.3.1.8. Dialogue with theDiagnostic Box

The Just ECU provides for thepossibility of connection with theDiagnostic Box for visualising themain control signals.

The r.p.m., the lambda oxygensensor signal and the STEP actu-ator position are actually visu-alised on the three LED bars ofthe device (par. 1.3.2).

1.3.1.9. Dialogue with the BRCPortable Computer

The Just ECU (through a spe-cial adapter) can also be con-nected to the BRC Por tab leComputer. A valid and powerfulinterface programme allows tocommunicate with the ECU andto have access to its memoriesand to its central processing unitin real time (par. 1.3.3).

1.3.1.10. Double possibility forsetting and starting operations

In the Just system two possi-ble “approaches” have been con-templated for setting and starting,to meet all the installers’ require-ments.

It is actually possible to gof rom an essent ia l set t ing-up(Chapter 3), only based on thechangeover switch and on theDiagnostic Box (which minimisestimes and adjustments) to a tar-geted and personalised setting-up (Chapter 4) , based on theinterface programme on comput-er (which a l lows the sk i l ledinstaller to personalise the sys-tem working to adjust it to themost varied requirements).

1.3.1.11. Self-configuration ofthe system to the vehicle sig -nals

The Just system is able toself-configurate to the differenttypes of vehicle signals (auto -matic acquisition of any type ofTPS signal, of revs signal andof lambda oxygen sensor sig -nal). This makes the ECU settingconsiderably easier, by eliminat-ing the installer’s error possibility(Chapter 3).

1.3.1.12. Self-adapting of thesystem

Sel f -adapt ing s t ra teg ieshave been implemented in theJust system according to thechanges of the car work ingconditions and characteristics,in order to assure the constantand permanent optimisation ofthe control potential (par. 3.8).

1.3.1.13. Check-up of the sys -tem

Each time the board cuts out,the ECU carries out a check-up

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of all its parameters and of the"state" of a l l the componentsbelonging to the Just system.

Such a condition is pointedout by the changeover switchthrough a shifting lighting ofcouples of LEDs from the cen -tre outwards and back.

(NOTE: it is anyway possibleto break off the check-up for asubsequent starting in case ofneed).

1.3.1.14. Troubleshooting

The Just system is able tocarry out a diagnostic of its work-ing in real time.

Possible errors or troubles arestored by the ECU and pointedout through a special encodingon the changeover switch LEDsas soon as they occur.

They are a lso s tored andmade accessible in the interfaceprogramme on computer.

The clearance of the errorsstored takes place automatical -ly when the car stops: if theircause is removed, they won’toccur at the subsequent start -ing, otherwise they will reap -pear.

1.3.2. DIAGNOSTIC-BOX

The Just ECU contemplatesthe possibility of connection withthe Diagnostic Box for visualisingthe main control signals.

The r.p.m., the lambda oxygen

sensor signal and the STEP actu-ator position are actually visu-alised on the three LED bars.

The Diagnostic Box is there-fore a very usefu l inst rument(indispensable i f the interfaceprogramme on computer is notused) for the system configura-tion and setting, as well as for thestarting and any future controlsand adjustments of the parame-ters.

The combined use of theDiagnost ic Box and thechangeover switch, particularlyallows the access to very usefulsetting domains such as the visu-alisation of the STEP actuatorreset position and the duty-cyclevisualisation and setting out ofthe lambda signal emulated (seeChapter 3 for the deta i leddescription).

1.3.3. INTERFACE PROGRAMME

ON COMPUTER

The possibility to connect theJust ECU to the BRC PortableComputer ( through a spec ia ladapter) has been contemplatedfor a more and more practicaland precise setting procedure.

A valid and powerful interfaceprogramme allows to communi-cate with the ECU and to haveaccess to its memories and itscentral processing unit in realtime.

The interface on computer istherefore the instrument throughwhich the installer interacts withthe whole Just system and will beable to “model” the gas equip-ment to adjust it to the car char-acteristics according to the differ-ent driving conditions.

The orderly collection of thefiles of the different installationsperformed will be real historicalarchives, very useful both to keepthe equipment evolution undercontrol in time, and to be a start-ing point for new similar or critical

installations.The Chapter 4 of this hand-

book is completely dedicated tothe interface programme on com-puter.

1.3.4. HARNESS

The Just ECU connection tothe system different elements canbe performed with two harnesstypes (see “C” Appendix for theattendant codes). The main con-nector of the Automotive 24-waytype gathers all the secondarypre-wired connectors and the dif-ferent wires, to which the samecolours used for the BRCLambda Gas systems have beenmaintained.

The different wires are more-over divided into sheaths in orderto make the installation easierand to improve the appearance.

1.3.5. GAS FLOW CONTROL

ACTUATOR

The control of the fuel quantitysent to the engine is carried outby the STEP actuator: it is a stepby step engine of common use inthe automotive field, to which acylindrical shutter is applied. Thestroke of this shutter provokes avariation of the gas passage portin the pipe (fig. 4).

The adjusting system is man-aged in every instant and in realtime by the ECU which controlsits work done, by valuing both thelambda oxygen sensor responseand the car working conditionsaccording to special preset maps,in case self-adapted, which cananyway be handled via software(reset position with the cold oxy-gen sensor, stoichiometric para-meters, cut-off working, at idlespeed, at normal speed, at fullload, management of accelera-t ions and decelerat ions andengine load).

The extreme decision-makingFig. 4STEP Actuator

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quickness of the digital systemand its flexibility assure an easyand effective setting for the con-stant maintenance of the correctstoichiometric ratio on every carand engine model. The actuatoris designed for running extremelywell both on CNG and on LPG.

1.3.6. REDUCER

The Just device is suitableboth for LPG and for CNG.

In any case, the LPG reduc -er-vaporiser or the CNG pres -sure reducer ought to be ofBRC manufacture, according tothe regulations in force whichprohibit combinations differentf rom those used dur ing theapproval tests.

1.3.7. MIXER

The above appl ies to themixer too: the mixers admittedare only those marked ”BRC”.

NOTE: the use of the Just sys-tem, through the in format ionpassed on by the Diagnostic Boxor rather, by the interface pro-gramme on computer, allows themore exper ienced instal ler tovalue possib le fa i lures of thefeeding mechanical system andi ts best locat ion and set t ingaccording to the di fferent carmodels.

1.4. ADVANTAGES OFTHE JUST SYSTEM

Your at tent ion has beenalready drawn several times tothe high potential of the microcon-troller system and of its settingand starting modes.

This paragraph resumes andsums up some of the most impor-tant goals we aimed at during theplanning, the development andthe realisation of the Just system.

1) The system is the result of

several years of experience andis due to a synthesis of the bestfeatures of the lambda gas controlsystems, opportunely integratedby innovative functions and defi-nitely in the lead.

2) The results attained by thesystem in the approval emissiontests of the product are evidenceof the exceptional quality of themixture control strategies: only amodern, valid and adaptable sys-tem can attain such goals.

3) The approval tests from thepoint of v iew of theElectromagnetic Compatibi l i ty(EMC), successfully passed bythe system, h ighl ighted i tsstrength to the electromagnetictroubles and confirmed the validi-ty of the planning and realisationstrategies.

4) The ECU, with a microcon-troller, manages the control of thewhole gas equipment and adjuststhe fuel quant i ty in feedbackthrough the STEP actuator inorder to obtain an optimum mix-ture, both in respect of pollutionand consumptions, and of drive-abi l i ty, aside from the outsideconditions (temperature, etc.) andthe fuel composition.

The adjusting system is actual-ly managed in every instant andin real time by the microcontrollerwhich controls its work done, byvaluing both the lambda oxygensensor response and the carworking conditions according tospecial preset maps, in case self-adapted, which can anyway behandled via software.

5)The Just system is able toself-configurate to the differenttypes of vehicle signals (automat-ic acquisition of any type of TPSsignal, of revs signal and of lamb-da oxygen sensor signal). Thismakes the ECU setting consider-ably easier, by eliminating theinstaller’s error possibility.

6) Sel f -adapt ing strategieshave been implemented in the

Just system according to thechanges of the car working condi-tions and characteristics, in orderto assure the constant and per-manent optimisation of the controlpotential.

7) The two possible “approach-es” for the setting and startingoperations have been studied tomeet all the installers’ require-ments. It is actually possible to gofrom an essential setting-up, onlybased on the changeover switchand on the Diagnostic Box (whichminimises times and adjustments)to a targeted and personalisedsetting-up, based on the interfaceprogramme on computer (whichallows the skilled installer to per-sonalise the system working toadjust i t to the most var iedrequirements).

8) The interface on computer,besides being the instrumentthrough which the demandinginstaller interacts with the wholesystem and is able to “model” thegas equipment to adjust it to thecar characteristics according tothe different driving conditions,also allows an orderly collectionof the files to the different installa-tions performed, creating real his-torical archives, very useful bothto keep the equipment evolutionunder control in time, and to be astarting point for new similar orcritical installations.

9) The ECU inlet and outletstages are dimensioned so that,by carefully following the circuitdiagrams supplied by the BRCservic ing and by carry ing outworkmanl ike sett ings, the caror ig inal petro l system can bedamaged in no way. and thediagnostic and control systemsare kept unchanged while driving.

10) The system good workingis constantly checked by the diag-nostic and check-up strategiesadopted and any possible anom-alies are promptly reported andstored.

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2.1. PRELIMINARY OPER-ATIONS

Before physically installing thedifferent components of the Justsystem, as before any new instal-lation, it’s a good rule to checkthe car running on petrol.

In particular, it is necessary tocarefully check the status of theignition electric equipment, theair filter, the catalyst; to checkthrough a multimeter or throughthe inst ruments BRC createdexpressly for instal lers (Jol ly,Diagnostic Box, …) the correctbehaviour of the different signalsconcerning the system: positiveafter contact, r.p.m., lambda oxy-gen sensor, TPS, petro l ECUstorage power supply, injectorspositive. It is also important tocheck that the earth power of thedifferent signals is stable andcoincides (the acceptable gapcan be of some 10 mV) with theone of the place where to con-nect the Just ECU earth.

Another very important warn-ing is to carefu l ly fo l low theinstructions enclosed to the BRCproducts and the circuit diagramssuggested by the Serv ic ing,obviously after having checkedthe car model to be converted,the production year, the enginenumber, the injection and ignitiontypes and therefore the equip-ment feasibility.

These are simple actions tak-ing a few minutes which couldavoid future inconveniences andcomplaints with a consequentwaste of time.

2.2. ECU FIXING

The Just ECU is proposedwith a case (though already wide-ly used and checked with theBRC Blitz ECU), consisting of aplastic body and an aluminiumfront which is robust, pret tysmall and watertight, thereforesuitable to be installed directlyinside the engine compartment.

The new 24-way connector ofthe automotive type also assuresa perfect tightness and a practi-cal coupling system.

For a correct installation, it isanyway necessary to carefullyfollow the directions here-below:

- try not to fix the ECU in sightof the exhaust mani fo ld : theradiative heat propagating coulddamage it even at a considerabledistance; it is therefore sufficientto have some walls interposedbetween the exhaust manifoldand the ECU, avoiding like thatthe direct radiation;

- it is anyway always neces-sary to install the ECU in an areaof the engine compartment whichis as much protected from wateras possible; in particular, i t isessential to fix it in such a way asto have the harness wi th the

sheaths turned downwards and toprevent the possible moisturefrom filtering inside the connec-tor, by dripping on the sheaths(fig. 5).

- try not to place the ECU nearthe spark plug cables or near thecoil high voltage cable.

The solution to fix the ECU,where it is possible, inside thedriver and passenger compart-ment, is anyway always allowed;in this case i t is necessary toavoid little ventilated areas, e.g.between felts, filled carpets, etc....

Use the special body tonguefor fixing and prevent other sys-tems from deforming the case;finally check there are no vibra-tions.

2.3. ECU CONNECTION

The Just ECU connection tothe different system elementsought to be carried out throughone of the two types of 24-poleharness supplied by BRC (see“C” Appendix for the attendantcodes).

The ECU also has a DIN 5-pole connector for the connection

2. INSTALLATIONOF THE SYSTEM

Fig. 5Installation of theJust ECU: correctpositioning

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to the Diagnostic Box.The possible connection to the

BRC Portable Computer for usingthe specific interface programme,can be carried out with a specialadapter (see “C” Appendix for theattendant codes), which has to beconnected to a connector insidethe ECU body (par. 2.3.2).

All the connections of theharness wires which are unpro -vided with connector ought tobe carried out through welldone and suitably insulatedsoft solderings. Do not twistthe wires simply or use scarce -ly reliable terminals.

The fo l lowing inst ruct ionshave general val id i ty and areindispensable for understandingthe system. Please refer to thespecific diagrams for the applica-tion to each car model. The 24-pole harness wires maintain thesame colours used in the otherBRC systems; the wi res aremoreover divided into severalsheaths in order to make theinstallation as easy as possible.

2.3.1. 5-POLE DIN CONNECTOR

FOR DIAGNOSTIC BOX

As previously said, the JustECU contemplates the possibilityof connection with the DiagnosticBox for visualising the main con-trol signals. The r.p.m., the lamb-da oxygen sensor signal and theSTEP actuator position are actu-ally visualised on the three LEDbars. The 5-pole DIN connector(fig. 7) just allows the ECU con-nection to the Diagnostic Box.

2.3.2. CONNECTION TO THE

BRC PORTABLE COMPUTER

As a l ready h in ted in theChapter 1, the possibility to con-nect the Just ECU to the BRC

Portable Computer is contemplat-ed for a more practical and closesetting procedure.

A valid and powerful interfaceprogramme allows to communi-cate with the ECU and to haveaccess to its memories and to itscentral processing unit in realtime.

The connection is carried outon the computer serial door, eventhrough the same interface cable

already used with the BRC FlyingInjection system.

An adapter is actually avail-able and it can be connected tosuch a cable on one end and to aspecial 4-way connector placedon the Just ECU card on theother (see “C” Appendix for theat tendant codes) . In order tocarry out this connection it is nec-essary to open the ECU body(fig. 8).

Fig. 8Just ECU connection to theBRC PortableComputer

Fig. 6Just ECU(connectors sideview)

Fig. 7DIN 5-pole connec-tor for DiagnosticBox

DIN 5-pole tap

adapter

24-pole harnessmale connector

PC-Fly Gas connecting cable

BRC PortableComputer

13

2.3.3. 24-POLE HARNESS

The two types of 24-pole har-ness (see “C” Appendix for theattendant codes) have on oneend a main 24-way connectorwhich gather all the secondaryconnectors and the d i f ferentwires, whose description you willfind in the following paragraphs.

2.3.3.1. 10-way connector forthe changeover switch

The 9-pole multipolar cableinside the harness, ended on a10-way connector, is used for thechangeover switch connection(fig. 9). It connects the ECU tothe changeover switch placed inthe driver and passenger com-partment; in order to make itspassage through the wall open-ings easier, the connector 90°bending on one side is recom-mended to make it parallel withthe wires.

The boxed changeover switchis the one already used in theother BRC systems (see “C”Appendix for the at tendantcodes).

2.3.3.2. 4-way connector for theSTEP control actuator

The 4-pole multipolar cableended on the 4-way connector(fig. 10) connects the ECU to thestep by s tep engine which isaimed at controlling the gas flow(par. 1.3.5 ).

2.3.3.3. Connection of the gaslevel sensor

The connecting cable for thesensors of the res is t ive typebelongs to the 24-pole harnessand is White/Black, ended with afemale faston provided with afaston cover. The connect ionbetween the ECU and the sensorcan be carried out through the

Fig. 11Level gauge of theresistive type

Fig. 11.AGas level gauge ofthe Hall effect type

Fig. 9Cable for the changeover switchconnection

Fig. 10Cable for the Stepactuator connection

White/Black

Resistive sensor

Shielded cable

Hall effect sensor

14

special extension cable containedin the packages of sensors (fig.11).

For the connection of the levelgauge of the Hal l effect type,there is a type of Just ECU (see“C” Appendix for the attendantcodes) provided with a special lit-t le cable coming out from thefront with the white 3-way con-nector (fig. 11.A).

For the connections, refer inany case to the inst ruct ionsenclosed to the sensors.

2.3.3.4. Startend Connector

It is present on all the versionsof the 24-pole harness of the Justsystem and cons is ts o f 3White/Green, Black, Red wires,ended on a male faston with itscover. These connections oughtto be used for linking any devicesof the Modular family, employedfor cutting and/or injectors emula-tion functions (fig. 12).

The devices of the Modularfamily can be fixed through thespecial “dovetail” on the ECUbody.

Do not feed any emulatorswith the Green wire feeding thegas solenoid valves, since thatway it shouldn’t be possible touse the fuel overlapping func -tion precisely managed by theJust ECU through theWhite/Green wire.

2.3.3.5. Reset connector

It is present on a version ofthe 24-pole harness (see “C”Appendix for the at tendantcodes) and consists of a 4-wayfuse-holder box (fig. 13) whichgathers the following couples ofcables:

- Yellow + Light blue= (lambda oxygen sensor),

- White + White/Orange= (memories),

- Red + Red

The fuse on the Red wi reought to be a lways correct lyinser ted as i t has the wholeequipment protecting function.

The fuses for the other twocouples of cables are housedinside the reset connector andought to be inserted in case ofserious failure of the gas equip-ment.

By inser t ing the fuses andposi t ion ing the changeoverswitch on the forced petrol posi-t ion, the car regularly runs onpetrol even i f the Just ECU isremoved.

The installer ought to give thesui tab le d i rect ions to the carowner on the use of this function.

Fig. 12Startend connectorand fixing of theModular devices

Fig. 13Resetconnector

Black

White/Green

Red

15

2.3.3.6. “A” Sheath

It is important that the BLACKwire is connected to the engineearth, not to the battery negativeor to other bodywork parts.Since from a point to another of thecar earth the potential can changeby some tenths of volt, by gettingthe negative in unfavourable points,you risk interpreting the lambdaoxygen sensor signal wrongly.

(*) The “type” shows whetherthe attendant signal is an inlet (in)or an outlet (out).

(**) The RED wire ought to beprotected by a 7,5 A fuse, shoulda harness unprovided with areset connector be used.

The loads on the GREEN wireare to be connected in parallel eachother.

2.3.3.7. “B” Sheath

The connection of the BROWNwire absorbs very little current, sothat any positive after contact canbe chosen. What is important isto check that it is not a point ofthe electric equipment subjectto strong losses of voltage. Forinstance, on some cars it is neces-sary not to use the ignition coilpositive or the injectors positivebecause they are preceded byresistances lowering the potentialby some volt.

The GREY wire ought to beconnected to a frequence impul-sive signal proportional to ther.p.m. It can be:

- a square wave signal findableon the injection ECU or on theigni t ion one, provided that i tsamplitude is sufficient. The suit-

able wires could be: the wire goingto the revolution counter or thewire connecting the above ECUswith the ignition power module;

- a signal coming from the"ignition coil negative".

When i t is possible, weadvise to always give prefer -

ence to the square wave sig -nals, by choosing the connec -tion to the “ignition coil nega -tive” only as extreme possibili -ty.

Do not twist the grey wire asan antenna on the high voltagecables.

Fig. 14“A” Sheath

Colour type (*) descriptionBlack in engine earthRed in battery positive(**)Green out LPG solenoid valve

solenoid valve on LPG or CNG reducersany safety solenoid valve on LPG tank(any) other devices

Colour type descriptionBrown in positive after contactGrey in engine ignition impulses

Fig. 15“B” Sheath

Black

Red

Engine earth

+12VBattery

Reducer S.V. LPG S.V.

Green

Tank S.V.

GreyEngine ignition impulses

Positive after contact Brown

16

2.3.3.8. “C” Sheath

The lambda oxygen sensorusually supplies a signal oscillat-ing f rom 0 and 1 V; on sometypes of cars it is possible to findoxygen sensors wi th s ignalsoscillating between 0,7 and 1,5 Vor between 0 and 5 V; the JustECU, with the self-acquisit ionprocedure, is able to adjust to allthese lambda signal amplitudesas well as to lambda oxygen sen-sors with absorption or resistivepull-up.

The connection of the YEL-LOW and LIGHT BLUE wires canbe carr ied out d i rect ly on theinjection ECU, or on the oxygensensor connector; in any case itis necessary to carefully followthe detailed diagrams of eachcar.

If it is necessary to emulatethe lambda oxygen sensor signal,the wiring diagram is the one offig. 16.A. If not, please refer tothe fig. 16.B.

Important: do not short-cir -cuit the oxygen sensor wireei ther towards the earth, ortowards the positive.

Do not apply any load.

When in doubt, the wire of thelambda oxygen sensor signal canbe easi ly located through the"Jolly" code 06LB00001086.

Colour type descriptionYellow in lambda oxygen sensor signalLight blue out emulated lambda signal

Fig. 16“C” Sheath

Fig. 16.ARead of theLambda oxygensensor signal withemulation

Fig. 16.BRead of theLambda oxygensensor signalwithout emulation

✂

Light blueLambda Signal Emulated

Lambda Signal Yellow

Light blueDo not connect

Lambda oxygen sensor

Injection ECU

Injection ECU

Lambda oxygen sensor

Oxy

gen

sens

or s

igna

lO

xyge

n se

nsor

sig

nal

Yellow

Light blue

Yellow

17

2.3.3.9. “D” Sheath

The WHITE and WHITE/ORANGE wires can have a dou-ble funct ion, conf igurable v iasoftware (see Chapters 3 and 4):

- Reset t ing funct ion of thepetro l in ject ion ECU memory(NP);

- NC relay contact function for(NC1/NC2) signal cutting.

The NP function of the Whiteand White/Orange wires is usual-ly only used on cars where it isnecessary to reset the petro linjection ECU memory. Such amemory is normally maintainedthrough a wire connecting directlythe injection ECU with the battery(see BRC specif ic diagrams).This wire is generally recognis-ab le because i ts vo l tage isalways 12V, with the ignition keyoff, with the ignition key on andwi th the engine running ( f ig .17.A).

Thanks to these connections,it is possible to interrupt it in time,by also preserving determinedfunctions as the self-cleaning ofthe hot wire, taking place someseconds after the engine stop-ping.

For using the NC1/NC2 func-tion (corresponding to the signalcut t ing relay contact) , p leaserefer to the specific diagrams ofeach car (fig. 17.B).

Be careful with the connec -tion polarity: in any case theWhi te /Orange wi re oughtalways to be connected to theone coming f rom the petro linjection ECU side.

Colour type descriptionWhite in ECU memories wire (battery side)White/Orange out ECU memories wire (ECU side)

Fig. 17“D” Sheath

Fig. 17.AMemories manage-ment (NP function)

+

Fig. 17.BRelay for cuttingwarning light signal(NC1/NC2 function)

White/OrangeECU memories wire

(ECU side)/NC1 relay contact

ECU memories wire(battery side)/

NC2 relay contact

White

White/Orange

Injection ECU

Mem

orie

s w

ire

+ 12VBattery

Injection ECU

Check light

White

White/Orange

White

18

2.3.3.10. “E” Sheath

The WHITE/VIOLET is to beconnected to the potentiometerproportional to the throttle bodyposition (TPS signal).

The TPS signal can be direct(voltage signal increasing whilethe throttle opening increases), orinverted (voltage signal decreas-ing whi le the throt t le openingincreases). It can moreover be ofthe analogic type (continuouslyvarying while the throttle positionvaries) or of the ON/OFF type(only assuming a minimum and amaximum value).

The Just ECU is able to recog-nise automatical ly (during thesel f -conf igurat ion procedure)whether the signal is direct orinverted. It is nevertheless nec -essary to set the TPS signaltype (analogic or ON/OFF) viasoftware (Chapters 3 and 4),knowing that the default con -figuration considers a signal ofthe analogic type.

2.4. ASSEMBLY OF THECHANGEOVER SWITCH

Choose a well accessible andvisible position for the driver andfix the device through the screwssupplied. By replacing the stickerwi th the spare one, thechangeover switch can also beassembled upright. By eliminatingthe outside body, the changeoverswitch can be directly boxed inthe car dashboard by using thespecia l dr i l l ing too l code90AV99000043.

Specia l boxed changeoverswitches are specifically availablefor each car, to be posit ionedinstead of the original switch cov-ering plates. Please refer to theelectric diagrams and to the pricelist for the available models.

2.5. ASSEMBLY OF THEGAS LEVEL GAUGE

Follow the instructions enclosedto the chosen transducer; regardingthe adjustment, also see the par.3.5.

2.6. ASSEMBLY OF THEGAS FLOW CONTROLACTUATOR

The STEP actuator ought to beassembled in any point of the gaspipe between reducer and mixer.We anyway advise to assemble itas near the mixer as possible . Italso ought to be mounted asupright as possible, with theconnector turned upwards (fig.19). Check there are no exces -sive vibrations and that theengine weight doesn’t restexcessively on the pipe.

2.7. ASSEMBLY OF THEMIXER

Follow the instructions suppliedfor each car and always use sole -ly BRC reducers .

2.8. ASSEMBLY OF THEREDUCER

Follow the usual assemblyrules, by fixing the reducer rigidly tothe bodywork and orienting it sothat the diaphragms are parallel tothe car longitudinal axle. Check thatno engine part hits the reducer, nei-ther when this one idles, or when itis under stress. Always try to placethe reducer and the mixer in such away as to reduce the gas pipelength as much as possible.

Colour type descriptionWhite/Violet in TPS (potentiometer integral with the throttle body)

Fig. 18“E” Sheath

Fig. 19Positioning recom-mended for theStep actuator.

Throttle valve potentiometer signal

White/Violet

NO NO

YES

19

In the Chapter 1 we told thatthe Just system setting and start-ing present two possib le“approaches”:

- system conf igurat ion andstar t ing only based on thechangeover switch and on theBRC Diagnostic Box;

- possibility to set up throughan interface programme on com-puter, in order to communicate inreal time with the ECU, allowing acareful control of the installationworking as well as a close andspecific setting.

In this Chapter the first possi-bility will be described in detail.Wi th the only use of thechangeover switch (which pre-sents manifold functions dedicat-ed to the installation setting andstar t ing in the Just system,besides the classical changingover and fuel level gauging func-tions) and of the Diagnostic Box itis actually possible to configurateand star t the whole system,thanks to special self-configurat-ing and self-adapting strategiesmanaged by the microcontroller.

3.1. THE DIAGNOSTIC BOX

The Just ECU contemplatesthe possibility of connection withthe Diagnostic Box for visualisingthe main control signals.

The Diagnostic Box is there-fore a very usefu l inst rument(indispensable if the interface pro-gramme on computer is not used)for the system configuration andsetting, as well as for the starting

and possible future controls andparameters adjustment.

The combined use of theDiagnost ic Box and of thechangeover switch also allows toaccede to par t icu lar set t ingdomains such as the visualisationand setting of the emulated lamb-da signal duty cycle (par. 3.6)and of the reset position of theSTEP actuator (par. 3.7).

3.1.1. VISUALISATION OF THE

SIGNALS ON THE LED-BARS

a – r.p.m.The above green LED-BAR

represents the r.p.m. When the r.p.m. signal acquisi-

tion and self-configuration phaseis over (par. 3.4.2), the LED-BARread jo ins the car revolut ioncounter read. The speed indica-tion supplied by the DiagnosticBox is therefore to be consideredapproximate.

b – Lambda oxygen sensorsignal

The second LED-BAR repre-sents the lambda oxygen sensorsignal.

The voltage supplied by thelambda oxygen sensor generallyvaries from zero to almost 1 volt,every LED of this bar thereforecorresponds to approx. 0.1 volt. Itis possible to reckon that the idealmixture corresponds to 0.4 ÷ 0.5volt, that’s why around these val-ues some green LEDs have beeninserted, being easy to be deter-mined, even whi le dr iv ing onroad. The mixture anywayremains excellent in the wholegreen field and good in the fieldmarked by the yellow LEDs.

Higher voltages turn the redLEDs on. These LEDs indicate arich mixture, whereas voltagesnearly zero volt can even turn allthe LEDs off.

In case of lambda oxygen sen-sors with a voltage varying from

0.7 to 1.5 volt or from 0 to 5 volt,the resolution of the representa-tion is obviously lower (approx.0.5 volt per LED in case of 0 ÷ 5volt oxygen sensors).

c – Position of the gas flowSTEP actuator

The th i rd ( red) LED-BARshows the working position of thegas flow STEP actuator, consist-ing of a step by step enginewhich, partially obstructing thepipe for the gas passage to themixer, allows to adjust the mix-ture.

The STEP position rangesfrom 0 (all closed) to 255 steps(all open) and the representa -tion given is not of the absolutetype, but of the relative one,according to the reset position.

On the LED-BAR, to have ahigher resolut ion, a 20-stepworking window is visualised. Itis centred around the STEPactuator current reset position.The reset posit ion is alwaysrepresented with 5 LEDs onand every more or less LED oncorresponds to 2 steps.

Consequently, for example, anonly LED on shows that the STEPis 7 ÷ 8 steps below the currentreset, whereas 9 LEDs on showthat the STEP is 8 ÷ 9 stepsabove the current reset.

Obviously, if the LED-BAR iscompletely on, the actuator is in aposition over 10 steps above thecurrent reset (considerable open-ing condition of the STEP due, forinstance, to the typically lean air-gas mixture strength, to an open-ing transient condition (pumping),or to a working condition at fullload).

Otherwise, if the LED-BAR iscompletely off, the actuator is in aposition ranging over 10 stepsbelow the current reset (consider-able c los ing condi t ion of theSTEP due, for instance, to thetypical ly r ich a i r -gas mixture

3. CONFIGURATIONAND SETTING OFTHE SYSTEM TOCHANGEOVER

20

strength, to a closing transientcondition, or to a cut-off workingcondition).

3.1.2. NUMERIC VISUALISATIONS

Besides the visualisation of thesystem main signals (with theLEDs turning on proportional tothe amplitude of the same signals)and of the STEP position relatingto the current reset, the threeLED-BARS of the Diagnostic Boxare also used, al l together, toobtain a precise representation ofparticular absolute numeric val-ues.

In these terms, both the exactnumeric value of the emulatedlambda signal duty-cycle (par. 3.6)and the one of the STEP currentreset position (par. 3.7) can bevisualised on the Diagnostic Box .

The encoding adopted for thispurpose is the following:

- the first LED-BAR showsthe hundreds, namely the num -ber of LEDs on starting from theleft side shows the hundreds;

- the second LED-BARshows the decimals, namely thenumber of the LED on startingfrom the left side shows thedecimals;

- the third LED-BAR showsthe units, namely the number ofLEDs on starting from the leftside shows the units.

The figure 20 depicts in outline,by way of example, a resetnumeric value = 125.

3.2. PRELIMINARY CON-TROLS

After the instal lat ion phaseaccording to the Chapter 2, inorder to start and adjust the carrunning on gas, it is necessary toconfigurate and set the system.

The first, indispensable stepto avoid serious failures anddangerous situations, ought

always to be a careful control ofthe installation of the mechani -cal parts (tank, reducer , mixer ,Step actuator , connecting pipes,etc.) with the empty tank. Thefollowing step is to introduce nomore than 4 ÷ 5 litres of gas inthe tank, which can be usedboth to check whether there areany leakages and to carry outthe first acquisition and self-configuration procedure (par.3.4), whose last phase (STEPactuator reset acquisition) is per-formed while the vehicle is runningon gas.

3.3. CONFIGURATION ANDSETTING DOMAINS

The Just ECU with a microcon-troller has been conceived in sucha way as to minimise the adjust-ments necessary to start theinstallation.

The system set-up is substan-t ial ly based on three differentphases:

- first acquisition and self-con-

figuration of the different signalsused by the ECU (TPS, revolutionsignals, lambda signal) and acqui-sition of the STEP actuator resetposition;

- additional manual setting withthe possibility to check and possi-bly correct the acquired valuesand/or the default values;

- self-adapting of the systemwhile the car working conditionsand characteristics are changing,to assure the constant and contin-uous optimisation of the controlstrategies.

In particular, the configurationand setting domains of the JustECU (the next paragraphs arededicated to) are the following:

- First acquisition and automat-ic self-configuration;

- Additional manual setting andparameters set-up;

- Visualisation and modificationof the emulated lambda signalduty cycle;

- Visualisation and modificationof the STEP actuator reset posi-tion;

- System diagnostic.

Fig. 21Changeover switch:identification of theLEDs

Fig. 20Numeric value onthe Diagnostic Box= 125

DIAGNOSTICBOX

GREEN LEDs

1° 2° 3° 4°

LED-BARS

TWO-COLOURED LED

125

21

3.3.1. LED READOUT ON THE

CHANGEOVER SWITCH

During the setting the TWO-COLOURED LED assumes differ-ent colours (Green, Red, Yellow)and different working conditions(on, off, blinking). The GREENLEDs are also used in differentworking conditions to allow a spe-cial encoding of the several settingphases. In this paragraph, andmore specifically in the fig. 21 and22, we intend to help the installerwith the interpretation of the mes-sages coming from the changeoverswitch.

The fig. 21 depicts thechangeover switch. The GREENLEDs can only assume a Greencolour with a fixed or blinking turn-ing on, whereas the TWO-COLOURED LED can each timeappear Green, Yellow, Red, fixed orblinking.

The fig. 22 contains the captionfor reading the messages suppliedby the changeover switch.

3.4. FIRST ACQUISITIONAND AUTOMATIC SELF-CONFIGURATION

At the first ignition, when thesetting operations have not beencarried out yet, if the changeoverswitch is in the central position,the GREEN LEDs blink two at atime alternatively and the TWO-COLOURED LED is off (fig. 23).In such conditions the vehicle isonly able to run on petrol.

Before using the gas ECU, itis necessary to carry out the firstacquisition and self-configura -tion procedure. W ith thechangeover switch in the petrolposition, the GREEN LEDs areoff and the TWO-COLOUREDLED is fixed red. In such condi -tions the vehicle normally runson petrol and the only visiblesignal on the Diagnostic Box is

the lambda oxygen sensor one.Before starting the procedure,

we strongly recommend to putthe changeover switch in thepetrol position, to start the vehi -cle and to warm the engine upwell. W ith the engine warmed upit will be sufficient to put thechangeover switch in the centralposition to start the self-configu -ration procedure.

The vehicle will keep on run -ning only on petrol.

The first acquisition and self-configuration procedure consists offour phases :

1) TPS signal acquisition andself-configuration (par. 3.4.1).

2) R.p.m. signal acquisitionand self-configuration (par.3.4.2).

3) Lambda oxygen sensor sig -nal acquisition and self-configu -ration (par. 3.4.3).

4) Step actuator reset positionacquisition (par. 3.4.4).

During the early three phasesthe vehicle only runs on petrol.

At the beginning of the fourthphase the system automaticallychanges over to gas and again topetrol when the phase is com -pleted.

The Step actuator reset posi -tion is therefore carried out whilerunning on gas.

To make its execution easier, theoperator is informed on the workprogress through a special encodingbased on the colours of the TWO-COLOURED LED: as a general rule,a colour is associated to each phaseand the TWO-COLOURED LEDturning on mode distinguishes thecondition of the phase in progressfrom the condition of the phase com-pleted (see “D” Appendix for sum-marising outlines).

NOTE: It is possible to breakoff the first acquisition and self-configuration procedure everymoment and to begin all overagain by simply putting thechangeover switch in the petrolposition and getting back to thecentral position.

Warning: should a workinganomaly occur (TWO-COLOUREDLED on, alternating green - yellow- red), in any moment of the firstacquisition and self-configurationprocedure, after trying to trou -bleshoot (par . 3.9), it is necessaryto turn the vehicle off, to discon -nect the ignition key and to beginall over again.

Fig. 22Caption for the interpretation of the changeover switch leds

Fig. 23Beginning of thefirst acquisition andself-configurationprocedure

GREEN LED Off

GREEN LED Blinking

GREEN LED Fixed

TWO-COLOURED LED Blinking Yellow

TWO-COLOURED LED Off

TWO-COLOURED LED Blinking Green

TWO-COLOURED LED Blinking RedTWO-COLOURED LED Fixed Green

TWO-COLOURED LED Fixed Red

TWO-COLOURED LED Fixed Yellow

Red/Green TWO-COLOURED LEDAlternating

Red/Green/Yellow TWO-COLOUREDLED Alternating

GG GG GGGG

22

3.4.1. ACQUISITION AND SELF-CONFIGURATION OF THE TPSSIGNAL

- After having warmed theengine up well with the changeoverswitch in the petrol position, leavethe engine idling and put thechangeover switch in the centralposition.

During this phase the vehicleonly runs on petrol.

- After approx. 10 ÷15 sec -onds, the TWO-COLOURED LEDturns on fixed red (beginning ofthe TPS acquisition phase) (fig.24).

- Accelerate uniformly andthoroughly 3 times

- During this phase the min. andthe max. TPS are determined andit is possible to ascertain whetherthe TPS signal is direct or inverted.

- If the operation has beencarried out correctly , the TWO-COLOURED LED turns red blink -ing and indicates the end of theTPS acquisition phase (fig. 25).

3.4.2. ACQUISITION AND SELF-CONFIGURATION OF THE R.P.M.SIGNAL

- After the TPS acquisitionphase (red blinking TWO-COLOURED LED), leave thechangeover switch in the centralposition and the engine idling(accelerator thoroughly released)and wait.

During this phase the vehicleonly runs on petrol.

- After approx. 5 seconds theTWO-COLOURED LED turns onfixed green (beginning of the r.p.m.signal acquisition phase) (fig. 26).

- Wait with the acceleratorthoroughly released (if the accel-erator is not released thoroughly,the acquisition is not carried out).

- During this phase the type ofr.p.m. signal used by the ECU isrecognised.

- After approx. 10 seconds the

Fig. 24TPS signal acquisi-tion and self-confi-guration

GG GGGG RRRR

Fig. 25End of the TPSsignal acquisition

GG GG GGGG RRRR

Fig. 26Acquisition and self-configuration of ther.p.m. signal

GG GG GGGG GGGG

Fig. 27End of the r.p.m.signal acquisition

GG GG GGGG GGGG

TWO-COLOURED LED turnsgreen blinking and indicates theend of the r .p.m. signal acquisi -tion phase (fig. 27).

- From now on, the r.p.m. indica-tion on the first LED-BAR of theDiagnostic Box is configurated cor-rectly (whereas so far it is likely notto correspond to the actual r.p.m.,according to the vehicle type).

WARNING: if you are sure that

there is no correspondencebetween the actual r .p.m. and theones visualised on theDiagnostic Box (error factor =1/4, 1/2, 2 or 4), it is advisable tobreak off the first acquisition andself-configuration procedure byputting the changeover switch inthe petrol position and to repeatby putting the changeover switchin the central position again.

GG

23

3.4.3. ACQUISITION AND SELF-CONFIGURATION OF THE LAMB -DA OXYGEN SENSOR SIGNAL

- After the r.p.m. signal acqui-sition, the acquisition and the self-configuration phase of the lambdaoxygen sensor starts.

During this phase the vehi -cle only runs on petrol.

- In order to enter the acqui -sit ion domain of the lambdaoxygen sensor , it is necessaryto constantly keep the engineat 3000 r.p.m.

- If the r .p.m. is kept on acorrect value, the TWO-COLOURED LED turns on fixedyellow and the acquisition phaseof the lambda oxygen sensorstarts (fig. 28).

- Every time you exit (on pur -pose or by mistake) from theacquisition r .p.m. window , theTWO-COLOURED LED becomesgreen blinking again and theacquisition of the lambda sig -nal is broken off.

To star t the acquis i t ionagain it is necessary to restorethe r .p.m. near the value wanted(3000 r.p.m.).

- The acquisition phase of thelambda s ignal has a var iableduration (from approx. 20 to 30seconds) according to the lambdaoxygen sensor type of the vehicle.

- During this phase it is possi-ble to determine the amplitude ofthe lambda oxygen sensor signal(0 ÷ 1 V; 0.7 ÷ 1.5 V; 0 ÷ 5 V), themax. and min. values of such asignal and the lambda oxygensensor type (normal, with absorp-tion, or with resistive pull-up).

- During the acquis i t ionphase the r .p.m. probably tendsto change and the lambda sig -nal on the Diagnost ic Boxremains fixedly rich or lean forsome seconds: this belongs tothe acquisition procedure andis not indicative of any failureof the vehicle.

Fig. 28Acquisition and self-configuration of thelambda oxygensensor signal

GG GG GGGG YYYY

Fig. 29End of the acquisi-tion of the Lambdaoxygen sensorsignal

GG GG GGGG YYYY

- The only operat ion theinstaller ought to carry out is tokeep the r.p.m. around the speci-fied value (3000 r.p.m.).

- If the setting phase of thelambda signal is successful,the TWO-COLOURED LED turnsyellow blinking and indicatesits conclusion (fig. 29).

24

3.4.4. ACQUISITION OF THE

RESET POSITION OF THE STEP

ACTUATOR

- After the acquisition phase ofthe lambda oxygen sensor (TWO-COLOURED LED blinking yel-low), go on keeping the engineat 3000 r.p.m.

- After approx. 3 seconds,the system automat ical lychanges over to gas and theTWO-COLOURED LED alterna -tively turns on red and green toindicate the beginning of theacquisition phase of the STEPactuator reset position (fig. 30).

- The reset search andacquisition are carried out onlyif the r .p.m. is outside the idlingand cut-off conditions, and thepermanence in the correct r.p.m.for the reset acquisition is contin-uously pointed out with the TWO-COLOURED LED alternativelyturning on red and green.

- Should the pre-establishedworking conditions be left, theTWO-COLOURED LED turns offand i t is then necessary torestore the suitable workingconditions of the engine.

- Keep the engine inside thesuitable r .p.m. window till thereset position acquisition is indi-cated.

- While the reset position isdetermined, the vehic lechanges over to petrol again,a l l the GREEN LEDs of thechangeover switch turn off andon the LED-BARS of theDiagnostic Box the reset posi -tion acquired is only indicatedwhereas respectively the r .p.m.signal, the lambda signal andthe step motor position aren’tanymore, according to theencoding already described inthe paragraph 3.1.2:

- the first LED-BAR shows thehundreds, namely the number ofLEDs on starting from the left sideshows the hundreds (typically no

LED or one LED on);- the second LED-BAR shows

the decimals, namely the numberof the LED on starting from theleft side shows the decimals;

- the third LED-BAR shows theunits, namely the number of LEDson star t ing f rom the lef t s ideshows the units.

I f , by way of example, thereset acquired is 85, the LED-BARS of the Diagnost ic Boxwould appear like in the fig. 31.

You are reminded that thestep motor posi t ion rangesfrom 0 (all closed) to 255 (allopen), with proper restrinctionson the max. possible ranges.

The search of the reset posi-tion is carried out starting from anactuator default reset position of100.

Until the searching phase ofthe reset position starts, the thirdLED-BAR constantly shows thisdefault reset position (100), withthe early 5 red LEDs on.

During the searching phase,the position visualised on the thirdLED-BAR is continuously updatedaccording to the STEP shift.

Since every LED correspondsto two steps, it is possible to visu-alise the STEP dynamics in a win-dow ranging from 90 to 110 steps.

In any case, the reset defini-tive position acquired is exactlyvisualised on the Diagnostic Box.

Once the reset position hasbeen acquired, the first acquisi -tion and self-configuration pro -cedure is over and all the val -ues acquired and the configura -tions done have been stored.

It is necessary to stop theengine and to turn the ignitionkey of f to get out f rom thedomain.

Fig. 30Acquisition of theStep actuator resetposition

GG GG GGGG GG RRGG RR

Fig. 31Visualisation of thereset acquired onthe Diagnostic Box

DIAGNOSTICBOX

85

25

3.5. ADDITIONAL MANUALSETTING AND PARAME-TERS SETUP

After the first acquisition andself-configuration phase, at thenext ignition the system is alreadyable to run on gas.

Before running the vehicle ongas, it is anyway necessary tocomplete the setting-up phasethrough a series of manual set -ting operations, some of themindispensable (such as the levelgauging adjustment, the configura-tion of the NP - NC1/NC2 relayand the ON/OFF analogic TPSsetting), others optional (such asthe changing over threshold andthe fuels overlapping time).

3.5.1. ACTIONS TO BE TAKEN

IN THE ADDITIONAL MANUAL

SETTING DOMAINS

To enter the domain dedicatedto the additional manual setting,the following operations are neces-sary:

- Start the engine and leave itidl ing with the changeoverswitch in the central positionand the vehicle running onpetrol (do not carry out the chang-ing over to gas).

- Start ing with thechangeover switch in the centralposition, do 3 petrol position >central position transitions in nomore than 3 seconds (you cannotstop for more than half a second inthe same position, otherwise youhave to start the whole sequenceagain).

- After the 3 transitions thefourth GREEN LED bl inks toindicate the entry in the firstmanual setting domain.

- The TWO-COLOURED LEDis off if the manual setting of thisdomain has never been carriedout, whereas it blinks if the set -t ing of the f irst domain hasalready been carried out at least

once.- The passage from a manual

setting domain to the next one isobtained by changing over fromthe central position > gas posi -tion.

(If you want, for example, toenter the fourth domain withoutsetting the previous ones, threesubsequent transitions from centralposition to gas position are neces-sary).

- The different domains (7altogether) are indicated by abinary code on the GREENLEDs.

- Once you have got to the lastmanual setting domain, a subse-quent transition of the changeoverswitch from the central position tothe gas position leads to the firstsetting domain again (cyclical man-agement).

- The acquisition or the set -t ing relat ing to the referreddomain is obtained by changingover from the central position >petrol position.

- For every manual settingdomain the TWO-COLOUREDLED assumes the fol lowingmeanings:

- off: the current domain hasnever been set;

- f ixed green (or red) on:acquisition relating to the cur -rent domain completed or inprogress;

- blinking green (or red): set -t ing relat ing to the currentdomain already carried out atleast once.

- To exit in any moment fromthe manual setting domain it isnecessary to disconnect theignition key .

The detailed description of thedifferent setting domains, of theattendant encoding on thechangeover switch LEDs and ofthe parameters acquisition modesis presented in the following para-graphs.

The condit ion of the TWO-

COLOURED LED depicted in thefigures of the following paragraphsrefers to the first time the additionalmanual setting domain is entered.

3.5.2. LOW LEVEL GAUGE

THRESHOLD SETTING (EMPTY

TANK)

When entering this sett ingdomain, refer to what have beenjust stated in the par. 3.5.1.

The setting domain is visualisedin the fig. 32 and is used for acquir-ing the fuel min. level.

Please remember that the con-dition of the TWO-COLOUREDLED quoted in the figure refers tothe first time this setting domain isentered.

The necessary operations arethe following:

- Carry out the setting opera -tions while the tank is empty .

- Put the changeover switchfrom the central position to thepetrol position to acquire thelevel currently present in thetank as the min. level; the TWO-COLOURED LED turns f ixedgreen (showing that the datum hasbeen acquired).

- Getting back to the centralposition, the TWO-COLOUREDLED turns blinking green (show-ing the setting already carried out)and will remain like that in the fol-lowing accesses to this settingdomain too.

Even if the setting operation hasalready been carried out, it is possi-ble to repeat it and to acquire anew value with the same acquiringprocess.

Fig. 32Low level gauge threshold setting

GG

26

3.5.3. 4/4 THRESHOLD OF THE

LEVEL GAUGE (80% FILLING)

When entering this settingdomain, refer to what has been stat-ed in the par. 3.5.1.

The setting domain is visualisedin the fig. 33 and is used for acquir-ing the 4/4 level of fuel.

Please remember that the condi-tion of the TWO-COLOURED LEDdepicted in the figure refers to thefirst time this setting domain isentered.

The necessary operations arethe following:

- Carry out the setting opera -tions while the tank is full (4/4).

- Put the changeover switchfrom the central position to thepetrol position to acquire thelevel currently present in the tankas the 4/4 level; the TWO-COLOURED LED turns fixedgreen (showing that the datum hasbeen acquired).

- Getting back to the centralposition, the TWO-COLOUREDLED turns blinking green (show-ing the setting already carried out)and will remain like that in the fol-lowing accesses to this settingdomain too.

Even if the setting operation hasalready been carried out, it is possi-ble to repeat it and to acquire a newvalue with the same acquiringprocess.

3.5.4. CHANGING OVER

THRESHOLD

When entering this sett ingdomain, refer to what has beenstated in the par. 3.5.1.

The setting domain is visualisedin the fig. 34 and is used for modify-ing the changing over threshold.

Please remember that the con-dition of the TWO-COLOUREDLED depicted in the figure refers tothe first time this setting domain isentered.

The necessary operations arethe following:

- Run the engine at the r .p.m.wanted (included between 1500and 4500 r.p.m.) and move thechangeover switch from the cen -tral position to the petrol posi -tion to acquire the current r .p.m.as the revolution thresholdabove which changing over togas is allowed; the TWO-COLOURED LED turns f ixedgreen (showing that the datum hasbeen acquired).

- Getting back to the centralposition, the TWO-COLOUREDLED turns blinking green (show-ing the setting already carried out)and will remain like that in the fol-lowing accesses to this settingdomain too.

Even if the setting operation hasalready been carried out, it is possi-ble to repeat it and to acquire anew value with the same acquiringprocess.

3.5.5. NP - NC1/NC2 RELAY

CONFIGURATION

When entering this sett ingdomain, refer to what has beenstated in the par. 3.5.1.

The sett ing domain is visu-alised in the fig. 35 and is used forchanging the contact configurationof the relay coming out from theWhite and White/Orange wires.

- The possible functions are thefunction of the “no-problem”(NP)device, for resetting the petrolinjection ECU memory, and thefunction of relay contact for cuttingthe (NC1/NC2) signal.

- The TWO-COLOURED LEDblinking green shows that thereis already a default setting andthis is the NP function.

- By putting the changeoverswitch from the central positionto the petrol position the currentsett ing-up of the relay ischanged, by selecting in thiscase the NC1/NC2 function, andthe setting-up is shown by thefixed red TWO-COLOURED LED.

- Getting back to the centralposition, the TWO-COLOUREDLED turns blinking red (settingcarried out and NC1/NC2 setting-up).

Even if the setting operationhas already been carried out, it ispossible to pass from a setting-upto another of the relay function, byrepeating the same process.

Warning: the NP – NC1/NC2relay setting-up ought to corre -spond to the conf igurat ionadopted in the connections ofthe harness to the ECU (see par .2.3.3.9).

3.5.6. FUELS OVERLAPPING

TIME

When entering this settingdomain, refer to what has been stat-ed in the par. 3.5.1.

The setting domain is visualisedin the fig. 36 and is used for modify-

Fig. 34Changing over threshold setting

GGGG

Fig. 35Configuration of the NP - NC1/NC2 relay

GG GG

Fig. 334/4 level threshold setting

GG

27

ing the fuels overlapping time whilechanging over from petrol to gas.

Please remember that the condi-tion of the TWO-COLOURED LEDdepicted in the figure refers to thefirst time this setting domain isentered.

- By putting the changeoverswitch from the central positionto the petrol position the TWO-COLOURED LED turns fixedgreen and the current fuels over -lapping time is visualised for 3seconds on the GREEN LEDs,according to the following encod -ing:

- no GREEN LED on: no over -lapping

- 1° GREEN LED on: 3 tenthsof second

- 2° GREEN LED on: 6 tenthsof second

- 3° GREEN LED on: 9 tenthsof second

- 4° GREEN LED on: 12 tenthsof second

- After 3 seconds, the overlap -ping time is continuouslyincreased by 3 tenths of secondeach time and the visualisationon the GREEN LEDs is updated(when 12 tenths are reached, startfrom the beginning and so on).

- By putting the changeoverswitch in the central positionagain, the currently visualisedoverlapping time is acquired andthe TWO-COLOURED LED turnsgreen blinking (showing the settingalready carried out).

In this case too it is possible torepeat the setting operation and toacquire a new value with the sameacquiring process.

3.5.7. ANALOGIC-ON/OFF

TPS SETTING-UP

When enter ing th is set t ingdomain, refer to what has beenstated in the par. 3.5.1.

The sett ing domain is visu-alised in the fig. 37 and is usedfor programming the TPS signaltype (analogic or ON/OFF) pre-sent on the vehicle.

- The TWO-COLOURED LEDblinking green shows that thereis already a default setting con -sidering the TPS of the analog -ic type.

- By putting the changeoverswitch from the central positionto the petrol position, the cur -rent TPS setting-up is changed,passing to the ON/OFF typeand the select ion done isshown through the fixed redTWO-COLOURED LED.

- Getting back to the centralposition, the TWO-COLOUREDLED turns red blinking (settingcarried out and TPS setting-up ofthe ON/OFF type).

Even if the setting operationhas already been carried out, it ispossible to pass from a setting-upto another of the TPS type, byrepeating the same process.

3.5.8. PARAMETERS SET-UP

When enter ing th is set t ingdomain, refer to what has beenstated in the par. 3.5.1.

The sett ing domain is visu-alised in the fig. 38 and is usedfor completely annulling any set-ting already carried out on thesystem. The necessary opera -

tions are the following:- Put the changeover switch

from the central position to thepetrol position.

- Remain in this position for5 seconds at least.

- Once the setup has takenplace, all the setting operationscarried out on the ECU havebeen completely cancelled.

- The second, the third and thefourth GREEN LED of the encod-ing and the TWO-COLOUREDLED remain fixedly on (fig. 39)and the three LED-BARS of theDiagnostic Box thoroughly turnoff.

After this operation it is nec -essary to switch the vehicle offand to reset the ECU complete -ly, by repeating the first acqui -sit ion and self-configurationprocedure too.

Warning! Perform the opera -tion only if you are really con -vinced!

3.6. DUTY CYCLE VISUAL -ISATION AND MODIFICA-TION OF THE LAMBDAOXYGEN SENSOR EMU-LATED SIGNAL

To enter the duty cycle visuali-sation and modification domain of

Fig. 36Fuel overlapping time setting

GGGG

Fig. 37On/Off-Analogic TPS setting

GG GG GG

Fig. 39Set-up done

GG

Fig. 38Parameters set-up

GG GG GG

GGGGGG

28

the lambda emulated signal, thefollowing operations are neces-sary:

- Connect the ignition keywithout start ing the vehicle,with the changeover switch inthe central position.

- Beginning wi th thechangeover switch in the cen -tral position, carry out 3 petrolposition > central position tran -sitions in no more than 3 sec -onds (you cannot stop for morethan half a second in the sameposition, otherwise you have tostart the whole sequence again).

- After the 3 transitions thechangeover switch LEDs are alloff, whereas the duty cycle percent value (0 ÷ 100%) of thelambda oxygen sensor emulat -ed signal is visualised on theDiagnostic Box, according tothe encoding already presentedfor the reset:

- the first LED-BAR shows thehundreds, namely the number ofLEDs on starting from the left sideshows the hundreds;

- the second LED-BAR showsthe decimals, namely the numberof the LED on starting from theleft side shows the decimals;

- the third LED-BAR shows theunits, namely the number of LEDson star t ing f rom the lef t s ideshows the units.

- The default value at the endof the first acquisition and self-configuration procedure is = 46(fig. 40).

- Putt ing the changeoverswitch from the central positionto the gas position, the currentduty cycle value is increasedby one (and the visualisation onthe Diagnostic Box is updated).

- Put t ing the changeoverswitch from the central position tothe petrol position, the currentduty cycle value is decreased byone (and the visualisation on theDiagnostic Box is updated).

- To acquire the new duty

cycle value it is necessary todisconnect the ignition key .

3.7. VISUALISATION ANDMODIFICATION OF THESTEP RESET POSITION

For enter ing the step resetposition visualisation and modifi-cation domain, the following oper-ations are necessary:

- With the changeover switchin the central position, start thevehicle on petrol and run theengine above 1500 r .p.m., with -out changing over to gas.

- In such conditions, begin -n ing wi th the changeoverswitch in the central position,carry out 3 petrol position >central position transitions inno more than 3 seconds (youcannot stop for more than half asecond in the same position, oth-erwise you have to start the wholesequence again).

- After the 3 transitions thechangeover switch LEDs are alloff, whereas the current resetposition is visualised on theDiagnostic Box, according tothe encoding already presented(par. 3.4.4).

- The accelerator can bethoroughly released and theengine can be left running onpetrol.

- Putt ing the changeoverswitch from the central positionto the gas position, the currentreset position is increased by

one (and the visualisation on theDiagnostic Box is updated).

- Putt ing the changeoverswitch from the central positionto the petrol position, the cur -rent reset position is decreasedby one (and the visualisation onthe Diagnostic Box is updated).

- The reset position cannot beover the pre-fixed thresholds.

- To acquire the new resetposi t ion i t is necessary toswitch the vehicle off.

- During the permanence inthis setting domain, the vehicleonly runs on petrol.

The use of such a sett ingdomain is only recommendedfor the reset visualisation. W eactual ly advise you against“ intu i t ive ly” modi fy ing thereset position value, since anypossible corrections have beenalready made by the self-adapt -ing procedure (par. 3.8).

3.8. SELF-ADAPTING

As we have already told in theChapter 1, particular self-adaptingstrategies have been implement-ed in the Just system while thevehicle working conditions andcharacteristics vary, in order toassure the constant and continu-ous optimisation of the controlpotential.

The properties and the fea-tures of such strategies can besummed up in two main aspects:

- constant contro l and

Fig. 40Duty-cycle defaultvalue of the lambdasignal emulated

DIAGNOSTICBOX

46

29

updating of the signals used bythe system, with any possiblecorrections in the configura -tions done during the first set -ting operation;

- dynamism and continuousupdating of the STEP actuatorreset posi t ion, able to sel f -adapt according to the changesin the car features and differentdriving conditions.

In particular, the reset self-adapting is aimed at optimisingthe mixture control in every situa-tion, by assuring a greater stabili-ty of the system at normal loadand a high prompti tude in thetransient conditions.

Another purpose of the resetself-adapting is to optimise itsposition rapidly in case a valuenot corresponding to the workingactual one has been acquiredduring the first acquisition. In thiscase, the reset meets the opti-mum one while driving on road.

3.9. SYSTEM DIAGNOSTIC

The Just ECU is provided witha self-diagnosing system indicat-ing the working anomalies with anencoding on the GREEN LEDsand alternating the green - yellow- red colours on the TWO-COLOURED LED.

Should any anomaly occur ,switch the vehicle off complete -ly, by disconnecting the igni -tion key too, and try to trou -bleshoot.

If the cause has been actuallyremoved, at the next ignition thesystem will work correctly again.

I f the cause has not beendetermined or removed, at thenext ignition, the anomaly noticedis likely to reveal itself again.

Should you not ice anyanomaly during the first acqui -sit ion and self-configurationprocedure, start such a proce -dure again from the beginning.

Should any anomaly occurwhile the vehicle is running ongas, this one goes on runningon gas, but the STEP actuatorstands in the reset posi t ion(control in the emergency con -ditions).

List of the working anomaliesand of the attendant encoding onthe changeover switch LEDs.

Lambda oxygen sensor sig -nal transitions not detected orlambda oxygen sensor workingincorrectly (fig. 41).

The anomaly is pointed out ifno oscillations of the lambda oxy-gen sensor are noticed for a pro-longed t ime, both in the f i rs tacquisition phase and while thevehicle is normally running ongas.

Problems in the connection ofthe gas solenoid valves (fig. 42).

This anomaly is a sign of work-ing problems of the gas solenoidvalves (there is a trouble on atleast one solenoid valve). Theproblem nature is to be sought inan interrupted connection, in adamaged solenoid valve or in asolenoid valve short-c ircui tedtowards the earth.

Fig. 41 - Anomaly of the lambda oxygensensor signal

GG GG YYRR

Fig. 42 - Anomaly of the gas solenoid valves

GG YYRRGG

Fig. 43 - Anomaly of the TPS signal

GG GG YYRR

Fig. 44 - Anomaly of the STEP actuator resetacquisition

GG GG GG YYRR

Problems on the TPS signalduring the first acquisition pro -cedure (still below a minimumthreshold or not connected cor -rectly) (fig. 43).

The TPS s ignal contro l ismade in the first acquisition andself-configuration phase and theanomaly is a sign of an incorrectconnection of the White/Violetwire (par. 2.3.3.10) or of a failureof the potentiometer proportionalto the throttle body position.

Error or problems in theacquisit ion procedure of theSTEP actuator reset position(fig. 44).

We have already stated thatthe STEP actuator cannot movebeyond certain opening and clos-ing limits. In particular the resetacquired during the first acquisi-tion phase ought to be included ina value window too.

If the anomaly is noticed, itmeans that the STEP actuatortries to move to an incorrect work-ing position, without managing toassure the control stoichiometry.

It is necessary to check theequipment wel l and to reckonwhether the reducer and themixer are damaged or wronglyinstalled.

30

Working problems of theECU EEPROM (fig. 45).

I f th is anomaly occurs, theECU is seriously damaged and itis not possible to try to find a rem-edy for the problem. Apply imme-diate ly to the BRC TechnicalServicing.

Fig. 45 - EEPROM Anomaly

GG GG GG GG YYRR

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