ta01z036i gas serviceraspinovka).… · difference between second rail pressure and manifold...

WWOORRKKSSHHOOPP HHAANNDDBBOOOOKK

TTAA0011ZZ003366II N. 2 del 13/05/2008

M.T.M. s.r.l.Società UnipersonaleVia La Morra, 112062 - Cherasco (Cn) - ItalyTel. +39 0172 48681Fax +39 0172 488237

2/41

INDEX

1. DIAGNOSTIC GUIDE

2. RANGE OF VALUES DISPLAYED WITH THE COMPUTER

3. LIST OF THE PINS OF SEQUENT ECUs

4. COMPONENTS DIAGNOSTIC

5. PROBLEMS - SOLUTIONS

6. ERRORS CODES - SEQUENT DIAGNOSTIC

7. NOMENCLATURE

3/41

PPAARRAAMMEETTEERR EEXXTTEENNDDEEDD DDEEFFIINNIITTIIOONNPPAARRAAMMEETTEERR OOFF SSEEQQUUEENNTT

HHAANNDDHHEELLDD PPCCPPHHYYSSIICCAALL MMEEAANNIINNGG MMEEAASSUURREE UUNNIITT

Supply stateSupplySt It shows if vehicle is in petrol or gas modeor if it’s in changeover

P1 PressureP1 Absolute pressure at injectors rail mbar

Manifold PressureP.Man - Map Absolute pressure in the intake manifold mbar

GAS TemperatureGAS Temperature Temperature read by the sensor situatedon the injectors rail °C

GAS LevelGAS Level Signal coming from the level sensorsituated on the multivalve mV

Throttle Position SensorT.P.S. Throttle potentiometer signal %

Pre-catalyst 1Lambda oxigen sensorLambda Pre Cat 1 Pre-catalyst 1 Lambda oxigen sensor signal mV

Pre-catalyst 2Lambda oxigen sensorLambda Pre Cat 2 Pre-catalyst 2 Lambda oxigen sensor signal mV

RPMRPM

D.C. Inj. Petrol

Engine rotation speed RPM

Duty Cycle petrol injectors Proportion between injection time calculated fromthe petrol ECU and engine cycle time %

Duty Cycle Gas injectorsD.C. Inj. Gas Proportion between injection time calculated fromthe Gas ECU and engine cycle time %

Injection time of petrol injectorsT.on Petrol Injection time calculated from the Petrol ECU ms

Injection time of gas injectorsT.on Gas Injection time calculated from the Gas ECU ms

Reference flowFlow Gas flow to supply at the engine, calculated fromthe Gas ECU

Engine water temperatureWater temperature Temperature read by the sensor situatedat water inlet of Genius reducer °C

P1 PressureP1 Bis Absolute pressure at inlet to second injectors rail(in case of two rails and two Genius) mbar

Post-catalyst lambda oxigen sensorLambda Post Cat Post-catalyst lambda oxigen sensor signal mV

Reference Duty CycleD.C. Ref Reference Duty Cycle %

Instant CorrectionError % Instant Correction %

Delta pressure (P1-MAP)Delta P Difference between rail pressureand manifold pressure mbar

Delta pressure bis (P1bis – MAP)Delta P bis Difference between second rail pressureand manifold pressure mbar

1. DIAGNOSTIC GUIDE

SSEEQQUUEENNTT PPAARRAAMMEETTEERRSS KKEEYY

Here’s the summary table of the parameters displayed by Sequent program.

2. RANGE OF VALUES DISPLAYED WITH HANDHELD COMPUTER

In this table are reported minimum, maximum and typical value of some signals you can display with Sequent program,useful to diagnose possible working problems.

ATTENTION:All pressures are noticed as absolute pressures, that’s to say:• 0 mbar meansabsolute vacuum;• atmospheric pressure is roughly 1000 mbar (at sea level) so, for instance:P1 = 1800 mbar means a pressure of roughly 800 mbar over the atmospheric pressure;P1 = 700 mbar means a depressure of roughly 300 mbar compared to the atmospheric pressure

4/41

MMIINNIIMMUUMM VVAALLUUEE MMAAXXIIMMUUMM VVAALLUUEESSIIGGNNAALL TTYYPPIICCAALL VVAALLUUEEMMEEAASSUURREE

UUNNIITT

600 3000P1 Pressure At idle: 1800-2000In O.L.: 2500 mbar

200 1000MAP manifoldpressure

At idle: 300 - 450In O.L.: 1000 mbar

Ambient temperature 80 - 90GAS Temperature from10 to 90 °C

20 1200GAS Level It changes according to the tank gas level mV

0 100T.P.S. Percentage values that increaseaccording to the throttle opening rise %

0 7000RPM It changes in accordance with vehicle RPM

0 100Duty Cycle petrolinjectors In O.L. ≤ 100 %

0 100Duty Cycle gasinjctors In O.L. ≤ 100 %

0 200Petrol injection time It changes in accordance with vehicle ms

0 200Gas injection time At idle > 3 ms ms

Ambient temperature 90 - 100Engine watertemperature From Ambient T - 100 °C

1000 2500Delta pressure(P1-MAP)

At idle: 1450 – 1550In O.L.: 1450 – 1550 mbar

5/41

3. LIST OF THE PINS OF SEQUENT ECU

In the following tables there is the Sequent ECU list of pins, showing if signal are at inlet or outlet.

1° Connector from Pin 1 to Pin 28DDEESSCCRRIIPPTTIIOONN SSIIGGNNAALLPPIINN TTYYPPIICCAALL VVAALLUUEESS CCOOLLOOUURR

Engine Water Temperature1 In accordance withEngine Water Sensor White/Red

Sensors Supply2 + 5 V Red

P1 Pressure Sensor Signal3 From 0,5 V A 3,5 V Green

Gas Temperature4 From 0,5 V A 2,5 V Yellow

Bank1 Lambda Oxygen Sensor5 In accordance with Sensor Type Yellow

Bank2 Lambda Oxygen Sensor6 In accordance with Sensor Type Yellow

Gas Level7 20 mV - 1200 mV White/Black

Bank1 Lambda Oxygen Sensor Emulation8 In accordance with Sensor Type Light Blue

Diagnostic9 ---------- White

N.C. ----------10 ---------- ----------

Crankshaft Low Signal Inlet11 Signal In Crankshaft L Blue

N.C. ----------12 ---------- ----------

Changeover switch13 Ground Purple

Led 1/4 changeover switch14 + 5 V Red

Led Gas Changeover switch15 + 12 V Pink

Back Sv Control16 Ground Green/Black

Front Sv Control17 Ground Green/Black

Gas Injector 1 Control18 G Injector Control Green/White

Battery19 Ground Black




Petrol Injector 1 Inj Side23 P Injector to Inj Control Orange




Fuse 5a Communication27 + 12 V RedPositive Relay/Positive Back Sv/Positive Front Sv/

Positive Gas Injectors/Modular Supply Ld28 + 12 V Green

6/41


Crankshaft low signal Outlet29 Crankshaft L Out Signal Blue/Black

Crankshaft high signal Outlet30 Crankshaft H Out Signal Pink/Black

Ground Sens Pts On Rail Ground Level31 Ground Black

Manifold Pressure Sensor32 In accordance with MAP sensor White

N.C. ----------33 ---------- ----------

Temperature 234 ---------- Black

Bank2 Lambda Oxigen Sensor Emulation35 In accordance with Sensor Type Light Blue

Throttle Position Sensor36 According to TPS sensor0 - 5 V or 0 -12 V White/Purple

Shielding collection Shield37 Ground ----------

N.C. ----------38 ---------- ----------

Crankshaft high signal Inlet - Revolution counter39 Signal In Crankshaft L Pink/GreySoldered

N.C. ----------40 ---------- ----------

Changeover switch G41 Ground with Gas Changeover switch Grey

Led 2/4 changeover switch42 + 5 V Blue

Led 3/4 changeover switch43 + 5 V White

Led 4/4 changeover switch44 + 5 V Brown

N.C. ----------45 ---------- ----------

Actuators Relay Control46 Ground White/Green

Buzzer Changeover Switch47 + 5 V Green

Led Petrol Changeover Switch48 + 5 V Yellow

N.C. ----------49 ---------- ----------

+12v Under Key50 + 12 V Brown

Petrol Injector 1 Ecu Side51 P Injector Control From Ecu Purple




Inner Modular Supply55 + 12 V White/GreenBattery Ground, Changeover Switch Ground,

Communication Ground56 Ground Black

7/41

3.2 SEQUENT 24 ECU

DDEESSCCRRIIPPTTIIOONN SSIIGGNNAALLPPIINN TTYYPPIICCAALL VVAALLUUEESS CCOOLLOOUURR

ECU supply from battery/injectors re-circulationA1 +12V Red

Gas injectors GroundB1 Ground Black

Solenoid Valve piloting OutletC1 Ground Green/Black

Gas injector 1 piloting OutletA2 G Injector control White/Green

Petrol injector 1 InletB2 P Injector Control From ECU Purple

Water TemperatureC2 From 0,5V to 3,5V Yellow



K-Line - Serial CommunicationC3 ---------- White


Petrol injector 3 InletB4 P Injector Control From ECU PurpleChangeover Switch and Sensors Serial

CommunicationC4 ---------- Green



Sensors supply +5VC5 +5V Red

Common positive petrol injectors, injectors sideA6 +12V White/Brown

Lambda Oxygen Sensor Analogic InletB6 In accordance with Sensor Type Yellow

Lambda Oxygen Sensor Analogic OutletC6 In accordance with Sensor Type Light Blue

Common positive petrol injectors, ECU sideA7 +12V White/Green

MAP Pressure Analogic InletB7 Da 0,5V a 4,5 V White

Water Temperature from Reducer Analogic InletC7 Da 0,5V a 2,5 V White

RPM InletA8 Revolution counter IN signal Grey

Gas Pressure Analogic InletB8 From 0,5V to 3,5V Green

ECU and Sensors GroundC8 Ground Black

8/41

3.3 SEQUENT 56 ECU


Engine water temperature1 From 0,5V to 3,5V Yellow

Pressure sensor supply+5V2 +5V Red

Pressure sensor Analogical input 3 From 0,5V to 3,5 V Green

Pressure sensor 2 Analogical input - Optional4 ---------- ----------Lambda Oxygen Sensor PRECAT 1 Signal Analogical

input 5 In accordance with Sensor Type YellowLambda Oxygen Sensor PRECAT 2 Signal Analogical

input 6 In accordance with Sensor Type Yellow

---------- ----------7 ---------- ----------

Actuators external relay control8 +12V White/Green

K-line – Serial communication9 ---------- White

---------- ----------10 ---------- ----------

Input from Crankshaft or Revolution counter11 Crankshaft or Revolution counter INsignal Grey

ECU SUPPLY +12V Vehicle battery 12 +12V Red

Signal TTL input from Changeover switch (COM)13 ---------- Green

Gas solenoid valve n°1 control14 Ground Green/Black

Gas Injector 1 Control15 G Injector control White/Green




Gas injectors ground19 Ground Black

Actuators re-circulation20 +12V Green





Petrol injector 5 (injectors side)25 P Injector Control to Inj Orange




9/41


MAP analogical input29 From 0,5V to 4,5 V White

Temperature sensor analogical input30 From 0,5V to 2,5 V White

Inertial switch inlet31 ---------- ----------

Temperature sensor 2 analogical input – PTS Optional32 ---------- ----------

Lambda Oxygen Sensor PRECAT1 Emulation Output 33 In accordance with Sensor Type Light Blue

Lambda Oxygen Sensor PRECAT2 Emulation Output 34 In accordance with Sensor Type Light Blue

---------- ----------35 ---------- ----------

TPS analogical input36 According to TPS sensor0 - 5 V o 0 -12 V

White/Purple

Screening for analogical signals shield / body37 Ground ----------

---------- ----------38 ---------- ----------

Ground from battery39 Ground Black

---------- ----------40 ---------- ----------

Voltage +12V under key41 +12V Brown

Gas solenoid valve 2 control42 Ground Green/Black

Petrol injector n°1 (ECU side)43 P Injector Control From ECU Purple

Petrol injector n°1 (injectors side)44 P Injector Control to Inj Orange



Gas injectors ground 247 Ground Black

Actuators re-circulation 248 +12V Green









10/41

3.4 SEQUENT 24 MY07 ECU

DDEESSCCRRIIPPTTIIOONN SSIIGGNNAALLPPIINN TTYYPPIICCAALL VVAALLUUEESS CCOOLLOOUURR

Actuators PositiveA1 +12V Green

Gas Injectors GroundB1 Ground Black

Supply +12V from Battery PositiveC1 +12V Red

Gas Injector 1 Piloting OutletA2 G Injector control White/Green

Petrol Injector 1 InletB2 P Injector Control From ECU Purple

Petrol Injector 1 OutletC2 P Injector Control to Inj Orange








Petrol Injector 4 OutletB5 P Injector Control From ECU Purple


K-Line – Serial CommunicationA6 ---------- White

Lambda Oxygen Sensor Analogical InletB6 In accordance with Sensor Type Yellow

Sensors Supply +5VC6 +5V Red

Gas Pressure Analogical InletA7 From 0,5 to 4,5 V Green

Map Pressure Analogical InletB7 From 0,5V to 4,5 V White

Water Temperature from Reducer Analogical InletC7 From 0,5V to 2,5 V White

RPM InletA8 Revolution counter IN signal Grey

Voltage +12V Under KeyB8 +12V Brown

Battery GroundC8 Ground Black

11/41

3.5 SEQUENT SDI ECU



Pressure sensor supply +5V2 +5V Red

Pressure sensor analogical input3 From 0,5V to 3,5 V Green

Pressure sensor 2 analogical input -Optional4 ---------- ----------Lambda Oxygen Sensor PRECAT 1 Signal Analogical

input 5 In accordance with Sensor Type YellowLambda Oxygen Sensor PRECAT 2 signal Analogical

input 6 In accordance with Sensor Type YellowLambda Oxygen Sensor POSTCAT

signal Analogical input7 ---------- ----------



Can Bus Line10 ----------


ECU Supply +12V Vehicle battery12 +12V Red

Signal TTL input from Changeover switch (COM)13 ---------- Green

Gas solenoid valve n°1 control14 +12V Green







Gas Injector 5 control21 G Injector control White/Green


Petrol injectors 5 positive23 P Injector positive White


Petrol injector n°2(injectors side)25 P Injector Control to Inj Orange




12/41


MAP Analogical Input29 From 0,5V to 4,5 V White

Temperature sensor Analogical Input30 From 0,5V to 2,5 V White

---------- ----------31 ---------- ----------

---------- ----------32 ---------- ----------

Lambda Oxygen Sensor PRECAT1 Emulation Output33 In accordance with Sensor Type Light Blue


---------- ----------35 ---------- ----------

TPS Analogical Input36 According to TPS sensor0 - 5 V or 0 -12 V

White/Purple

---------- ----------37 ---------- ----------

Can Bus Line38 ---------- Yellow/Black


---------- ----------40 ---------- ----------

















13/41

3.6 SEQUENT PLUG & DRIVE ECU



Pressure sensor supply +5V2 +5V Red

PTS Pressure sensor analogical input 3 From 0,5V to 3,5 V Green

---------- ----------4 ---------- ----------Lambda Oxygen Sensor PRECAT 1 Signal Analogical

input5 In accordance with Sensor Type YellowLambda Oxygen Sensor PRECAT 2 signal Analogical

input6 In accordance with Sensor Type Yellow

---------- ----------7 ---------- ----------



Can BUS – Socket OBD connection10 ---------- Yellow


ECU Supply +12V Vehicle battery12 +12V Red

Socket OBD connection – K-line13 ---------- White

Gas solenoid valve n°1 control14 Ground Green/Black















14/41


MAP Analogical Input29 From 0,5V to 4,5 V White

PTS Temperature sensor Analogical Input30 From 0,5V to 2,5 V White

---------- ----------31 ---------- ----------

---------- ----------32 ---------- ----------



---------- ----------35 ---------- ----------

---------- ----------36 ---------- ----------

External spark advancer control37 +12V Green

Can BUS – Socket OBD connection38 ---------- Yellow/Black


Inner modular supply40 ---------- White/Black

















15/41

4. COMPONENTS DIAGNOSTIC

4.1 GAS INJECTOR

Coil resistance check

Signals check

Working check

Entering the Actuators Test section of Sequent program you can check the gas injectors good working.If you run this test on gas injector 1 for instance, you can pilot it, checking in this way its good working. If nothing happens after you send the control, then there is a problem on the injector controlled (gas injector 1, in theexample) and it is necessary to check and eventually to replace the gas injector, the wiring or the gas ECU.

4.2 GAS/PETROL INJECTORS TIMING

For the good working of the system, it’s necessary to have a perfect parallelism between injectors, so that the petrolinjector 1 signal is the one that guides the gas injector1 and so on. A timing not correct involves problems during thechangeover and in all tip-in situations.Correction procedure for injectors wiring errors:

Entering the Diagnostic > Actuators Test section of Sequent program, proceed as following:1. Deselect all the injectors cells. Now, the engine will run completely in petrol mode.2. Select the injector 1 cell. 3. If gas injector 1 inject in the right cylinder (the one corresponding to the petrol injector named 1), engine will run in theright way. In this case, repeat the procedure from step 1 for the next injector. If instead there is a problem, proceed withstep 4.4. Selectioned gas injector must be moved: you have just to move its connector on another gas injector, until the rightworking of the engine.5. Repeat procedure from step 1 with all the others injectors, until find the right position for all the gas injectors connec-tors.You can apply this procedure with the following systems: Sequent standard, Sequent Fast, Sequent FastNess, Sequent56, Sequent Direct Injection, Sequent Plug&Drive.For Sequent 24 MY07 system, it is more difficult to recognize the injectors sequence because of its semi-sequential injec-tors changeover, so that injectors break will take two injectors a time (1 and 4, 2 and 3). For Sequent 24 system you cannot use this diagnostic because the petrol injectors cut has made by the common positivewire of injectors control.

MMEETTHHOODDOOLLOOGGYY IINNSSTTRRUUMMEENNTTVVEERRIIFFIICCAATTIIOONN TTYYPPIICCAALL VVAALLUUEESS WWAAVVEE SSHHAAPPEESS

Check resistancebetween the two injector

clampsTester, Multimeter.Disconnected

Injector Connector 2 Ω ------------


Check signals fromtheinjector clamps Tester, Oscilloscope.Engine switched on

in LPG mode

Green: 11-14V

White\Green: injector signalas sideways

16/41

4.3 BACK AND FRONT GAS SOLENOID VALVE

Coil resistance check

Signals check

Working check

In order to verify the good working of front and back solenoid valve you can use two strategies.

1° PROCEDURE:

Back SV: after disconnecting the front solenoid valve inlet pipe, by using the Actuators Test section of Sequent programyou can excite the back solenoid valve coil. Now you should hear the back Sv clickand you should also have a gas leaka-ge from the exhaust pipe previously deconnected. If this doesn’t happen, it is necessary to check and eventually to repla-ce the electric coil, the wiring or the Gas ECU.

Warning: After the test connect again the exhaust pipe and check if there are leakages by means ofthe “Effe 91” spray

Front Sv: after disconnecting the front solenoid valve outlet pipe, by using the Actuators Test section of Sequent program,you can excite the front solenoid valve coil and, in this way, open it. Now you should hear the front Sv click and youshould also have a gas leakage from the Sv outlet. If this doesn’t happen, it is necessary to check and eventually toreplace the front solenoid valve, the wiring or the Gas ECU.

Warning: After the test connect again the exhaust pipe and check if there are leakages by means ofthe “Effe 91” spray


Check resistancebetween the two sole-

noid valve clampsTester, Multimeter.Disconnected coil

connectorFront (red): 9,5-10 ΩBack: 11,8 – 12,2 Ω ------------


Check signals fromthesolenoid valve injector

clampsTester, Oscilloscope.Engine switched on

in LPG mode

Tester, Green: 11-14V

Green/Black: Groundsupplied by the ECU

------------

17/41

2° PROCEDURE: Close the tap situated on the multivalve gas outlet and after switching the vehicle on and changing over toLPG, consume all the unburnt gas present in the tank. Switch the vehicle off and let the control board turned on. On thehandheld PC, in Diagnostic/Data Visualization section, P1 pressure value will be decreased at about 1000 mbar, that’s tosay at the atmospheric pressure value. This should mean gas absence in the pipes.Now you can open again the multivalve tap.

Through the Actuators Test, by acting first on back solenoid valve control and then on the front one, you should see theP1 pressure increase (that you can display in Diagnostic-Data Display). If this doesn’t happen, it is necessary to checkand eventually to replace the front or back solenoid valve, the wiring or the Gas ECU.

4.4 PRESSURE SENSOR

Signals check

Working check

PTS measures pressure and LPG temperature inside the rail. You can check the right working by means of Sequent pro-gram.

P1 Pressure: in Diagnostic\Data Visualization section you can display P1 Pressure value of the LPG in the rail. Pressurevalue at idle in LPG mode should amount at about 1800-2000 mbar, that’s to say the MAP value (300-450 mbar) +Genius reducer Delta-P (1450-1550 mbar). You can obtain a further control on PTS sensor by reading the pressure valuewith empty Gas loop.Close the tap situated on the multivalve gas outlet and after switching the vehicle on and changing to LPG, consume allthe unburnt gas present in the tank.Switch the vehicle off and let the control board turned on.In Diagnostic/Data Visualization section, P1 pressure value will be decreased at about 1000 mbar, that’s to say at theatmospheric pressure value. If this doesn’t happen, it is necessary to check and eventually to replace the PTS sensor,the wiring or the Gas ECU.


Check signals fromSensor clamps Tester, Oscilloscope.

Connected sensorconnector+Car swit-

ched on in gasmode

Red: 5 VBlack: Ground

Green: 2 V – 2,5VWhite: 0,6 V – 2,5 V

------------

18/41

4.5 LEVEL SENSOR (LITTLE WINDOW SITUATED ON THE MULTIVALVE)

Little Window Resistance Check

Signals check

Working check

Entering the Setting up\Level Calibration section of Sequent program you can set up at your discretion level indication onthe 4 LEDs.

4.6 ACTUATORS RELAY

Actuators Relay provides supply (Green) at all the system actuators when vehicle change to LPG. White\Green control isa ground and comes directly from the Sequent ECU when you change to LPG.


Check resistancebetween the two clamps

of wiring coming fromthe tank

Tester, Multimeter.Disconnected LittleWindow Connector

Full tank: 0 Ω

Tank 80%: 90 Ω------------


Check signals on wiringcoming from the tank Tester, Oscilloscope.

Connected LittleWindow

Connect.+Car tur-ned on in gas mode

Tester, Full tank: 45 mV

Tank 80%: 990 mV------------

GreenRELAY

N.C.Green

Red

Red

30 30

86

86

87

87

858587a 87a

N.C.

Red Red

White/Green

White/Green

19/41

Check signals at rest (Petrol mode)

Check signals in LPG mode

Working check

Entering the Actuators Test section of Sequent program you can checkthe actuators relay good working. Running thistest you can pilot the actuators relay in an intermittent way and check its good working.If nothing happens after you send the control, then there is a problem on the actuators relay control and it is necessary tocheck and eventually to replace the actuators relay, the wiring or the gas ECU.


Check signals on Relayterminals Tester, Oscilloscope.Vehicle in petrol

modeRed (86-30): 11-14V

green: no signalWhite\Green: 12 V

------------


Check signals on Relayterminals Tester, Oscilloscope.Vehicle in LPG

mode

Red (86-30): 11-14VGreen: 11-14V

White\Green: Groundsupplied from the ECU

------------

20/41

5. PROBLEMS AND SOLUTIONS

PROBLEMS SOLUTIONS

1 Vehicle doesn’t change over

2 Vehicle stalls while changing over to gas

3 Vehicle doesn’t start up or works wrongly in petrol

4 Changeover switch doesn’t switch on

5 A/More level LED/LEDs doesn’t/don’t work

6 Vehicle works wrongly at idle

• Changeover switch is in Petrol forced mode (Red LED tur-ned on)

• This changeover conditions are not valid:- Engine water temperature- Time since the starting

• Verify pressures• Verify Gas Solenoid valve working

• Verify the 15A fuse• Verify connections on the actuators relay• Replace the relay• Verify gas injectors working• Verify Gas ECU

• Verify injectors cut wiring• Verify Gas ECU

• Verify changeover switch wiring continuity• Replace the 5A fuse• Replace the changeover switch• Verify the ECU working

• Verify changeover switch wiring or replace indicator LEDs• In these cases, the cause could also be the ECU, therefo-

re verify that it communicates with PC interface and even-tually try to replace it

• One or more injectors don’t work correctly; check itsworking with Actuators Test

• Verify wirings of Gas injectors controls• Verify pressures and signals by means of Sequent pro-

gram

21/41

7 Computer doesn’t communicate

8 Changeover swtich doesn’t display GAS level

9 There’s smell of gas

10 Vehicle starts up wrongly in petrol mode

11 Vehicle changes over in petrol mode during tip-in(Enabled Buzzer)

12 Fuse 5A burns out

13 Vehicle changes over in petrol mode (Disabled Buzzer)

• Turn the vehicle control board on• Check the 5A - 15A fuse• Replace the communication wire• Replace Gas ECU• Check Communication section on PC

• LEDs don’t work• Verify ECU• Verify level wiring

• Check leakages with spray “Effe 91”

• Verify possible gas leakages inside the manifold: with theComputer verify P1 pressure value before starting up thevehicle. If it was 1000 mbar (Atmosferic Pressure) youcould have a gas leakage inside the manifold.

• Verify gas injectors good working• Verify Gas reducer: check possible gas leakage thanks to

the feedback inside the manifold

• Verify with the Computer Delta-P and P1 Pressure trend• Verify gas quantity and pressure inside the tank• Verify possibles narrowings in gas pipes• Verify System filter choking

• Verify fuses position5A on red wires sect. 1.515A on red wires sect. 2.5

• Verify short-circuits

• Verify RPM signal• Verify Gas Temperature signal• Verify continuity of RPM taking signal grey wire.• Verify temperature sensor working• Replace Temperature sensor• Replace gas ECU• Verify system supplies

22/41

6. ERRORS CODESSEQUENT DIAGNOSTIC

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.

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1-Er

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mod

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dve

rify c

redib

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lues;

3-Ch

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mem

ory.

Poss

ible

caus

es:

1-M

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in sh

ort-c

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with

pos

itive

sup-

ply;

2-M

APse

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is fa

ulty;

3-Se

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is fa

ulty.

Repa

iring

pro

cedu

re:

1-Ch

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APse

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conn

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Verif

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sho

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betw

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MAP

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and

pos

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supp

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;4-

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mem

ory.

Poss

ible

caus

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The

sens

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softw

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3-M

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4-Se

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5-Er

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ano

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(see

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e).

Repa

iring

pro

cedu

re:

1-Ve

rify M

APse

nsor

settin

g;2-

If yo

u ha

ve a

not

-reas

onab

le er

ror o

n P1

pre

ssur

ese

nsor

too,

follo

w sa

me

indi

catio

ns s

uita

ble

for

erro

r P11

90;

3-If

you

have

an

erro

r on

TPS

too,

follo

w sa

me

indi-

catio

ns su

itable

for e

rror P

1120

;4-

If yo

u ha

ve a

n er

ror o

n se

nsor

s sup

ply te

nsion

, fol-

low th

e sa

me

indica

tions

suita

ble fo

r erro

r P16

08;

5-Re

place

MAp

sens

or;

6-Re

place

Seq

uent

ECU

.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

r;2-

Star

t the

eng

ine, c

hang

e ov

er to

gas

mod

e an

dve

rify c

redib

ility o

f rea

d va

lues;

3-Ch

eck e

rrors

mem

ory.

23/41

24/41

Dia

gnost

ic g

uid

e

2. DT

C P1

115 W

ater

tem

pera

ture

sens

or (T

H 2O)

It is

poss

ible

to d

iagno

se th

e fol

lowi

ng fa

ilure

s:Si

gnal

valu

e und

er m

inim

um th

resh

old

Not r

easo

nabl

e sig

nal

Sign

al va

lue o

ver m

axim

um th

resh

old

Poss

ible

caus

es:

1-TH

2O si

gnal

wire

is n

ot co

nnec

ted;

2-Se

quen

t ECU

is fa

ulty;

3-W

ater

tem

pera

ture

sens

or is

fault

y;4-

TH2O

sign

al wi

re is

in s

hort-

circu

it wi

th p

ositiv

esu

pply.

Repa

iring

pro

cedu

re:

1-Ch

eck

the

weldi

ng in

the

takin

g po

int o

f the

TH2

Osig

nal;

2-Ch

eck

abse

nce

of s

hort-

circu

it be

twee

n TH

2Osig

nal w

ire a

nd n

egat

ive su

pply;

3-Ch

eck

the

TH20

sign

al wi

re c

ontin

uity

from

the

sens

or c

onne

ctor (

or s

ignal

takin

g po

int) t

o ga

sEC

U co

nnec

tor.;

4-Re

place

Seq

uent

ECU

.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

r;2-

Star

t the

eng

ine, c

hang

e ov

er to

gas

mod

e an

dve

rify c

redib

ility o

f rea

d va

lues;

3-Ch

eck e

rrors

mem

ory;

4-Re

pet t

his o

pera

tion

afte

r som

e m

inute

s in

idle

cond

itions

or a

fter d

riving

at le

ast f

or 5

km.

Poss

ible

caus

es:

1-TH

2O s

ignal

wire

is in

sho

rt-cir

cuit

with

neg

ative

supp

ly;2-

Sequ

ent E

CU is

fault

y;3-

Wat

er te

mpe

ratu

re se

nsor

is fa

ulty.

Repa

iring

pro

cedu

re:

1-Ch

eck

abse

nce

of s

hort-

circu

it be

twee

n th

e TH

2Osig

nal w

ire a

nd th

e ne

gativ

e su

pply;

2-Re

place

Seq

uent

ECU

.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

r;2-

Star

t the

eng

ine, c

hang

e ov

er to

gas

mod

e an

dve

rify c

redib

ility o

f rea

d va

lues;

3-Ch

eck e

rrors

mem

ory;

4-Re

pet t

his

oper

atio

n af

ter s

ome

min

utes

in id

leco

nditio

ns o

r afte

r driv

ing a

t leas

t for

5 km

.

Poss

ible

caus

es::

1-Se

nsor

settin

g is

not c

orre

ct;2-

Sequ

ent E

CU is

fault

y;3-

Wat

er te

mpe

ratu

re se

nsor

is fa

ulty;

4-Er

ror d

ue to

ano

ther

dev

ice fa

ilure

(see

Rep

airing

proc

edur

e).

Repa

iring

pro

cedu

re:

1-Ch

eck t

he T

H2O

sens

or se

tting;

2-If

you

have

a n

ot-re

ason

able

erro

r on

gas

tem

pe-

ratu

re s

enso

r too

, foll

ow th

e sa

me

indica

tions

sui-

table

for

erro

r P11

80;

3-If

you

have

an

erro

r on

sens

or s

upply

tens

ion, f

ol-low

the

sam

e ind

icatio

ns su

itable

for e

rror P

1608

;4-

Repla

ce S

eque

nt E

CU.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

r;2-

Star

t the

eng

ine, c

hang

e ov

er to

gas

mod

e an

dve

rify c

redib

ility o

f rea

d va

lues;

3-Ch

eck e

rrors

mem

ory;

4-Re

pet t

his o

pera

tion

afte

r som

e m

inute

s in

idle

cond

itions

or a

fter d

riving

at le

ast f

or 5

km.

25/41

Dia

gnost

ic g

uid

e

3. DT

C P1

120 T

PS T

hrot

tle P

oten

tiom

eter

(Thr

ottle

Pos

ition

Sen

sor)

It is

poss

ible

to d

iagno

se th

e fol

lowi

ng fa

ilure

s:Si

gnal

valu

e und

er m

inim

um th

resh

old

Not r

easo

nabl

e sig

nal

Sign

al va

lue o

ver m

axim

um th

resh

old

Poss

ible

caus

es:

1-TP

S sig

nal w

ire is

in s

hort-

circu

it wi

th n

egat

ivesu

pply;

2-PS

sign

al wi

re is

not

conn

ecte

d;3-

Sequ

ent E

CU is

fault

y;4-

TPS

pote

ntiom

eter

is fa

ulty.

Repa

iring

pro

cedu

re:

1-Ch

eck t

he ri

ght c

onne

ction

of t

he T

PS si

gnal

wire

;2-

Chec

k th

e ab

senc

e of

sho

rt-cir

cuit

betw

een

TPS

signa

l wire

and

neg

ative

supp

ly;3-

Chec

k the

TPS

sign

al wi

re co

ntinu

ity fr

om th

e se

n-so

r con

necto

r (or

sign

al ta

king

point

) to

the

gas

ECU

conn

ecto

r;4-

Repla

ce S

eque

nt E

CU.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

r;2-

Star

t the

eng

ine, c

hang

e ov

er to

gas

mod

e an

dve

rify c

redib

ility o

f rea

d va

lues;

3-Ch

eck e

rrors

mem

ory.

Poss

ible

caus

es:

1-TP

S sig

nal w

ire is

in s

hort-

circu

it wi

th p

ositiv

e su

p-ply

;2-

Sequ

ent E

CU is

fault

y;3-

TPS

pote

ntiom

eter

is fa

ulty.

Repa

iring

pro

cedu

re:

1-Ch

eck

the

abse

nce

of s

hort-

circu

it be

twee

n TP

Ssig

nal w

ire a

nd p

ositiv

e su

pply;

2-Re

place

Seq

uent

ECU

.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

r;2-

Star

t the

eng

ine, c

hang

e ov

er to

gas

mod

e an

dve

rify c

redib

ility o

f rea

d va

lues;

3-Ch

eck e

rrors

mem

ory.

Poss

ible

caus

es:

1-Se

nsor

settin

g is

not c

orre

ct;2-

Erro

r due

to a

noth

er d

evice

failu

re (s

ee R

epair

ingpr

oced

ure)

;3-

Sequ

ent E

CU is

fault

y.

Repa

iring

pro

cedu

re:

1-Ch

eck t

he T

PS se

nsor

settin

g;2-

If yo

u ha

ve a

n er

ror o

n se

nsor

sup

ply te

nsion

, fol-

low th

e sa

me

indica

tions

suita

ble fo

r erro

r P16

08;

3-Re

place

Seq

uent

ECU

.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

r;2-

Star

t the

eng

ine, c

hang

e ov

er to

gas

mod

e an

dve

rify c

redib

ility o

f rea

d va

lues;

3-Ch

eck e

rrors

mem

ory.

26/41

Dia

gnost

ic g

uid

e

4. DT

C P1

130 e

P11

50 P

RECA

T 1 L

ambd

a Oxig

en S

enso

r (sig

nal)

and

PREC

AT2 L

ambd

a Oxig

en S

enso

r (sig

nal)

It is

poss

ible

to d

iagno

se th

e fol

lowi

ng fa

ilure

s:No

t rea

sona

ble s

igna

lSi

gnal

valu

e ove

r max

imum

thre

shol

d

Poss

ible

caus

es:

1-PR

ECAT

1 (o

r PRE

CAT

2) si

gnal

wire

is in

shor

t-circ

uit w

ith p

ositiv

e su

pply;

2-Se

quen

t ECU

is fa

ulty;

3-PR

ECAT

1 (o

r PRE

CAT

2) la

mbd

a ox

igen

sens

or is

fault

y.

Repa

iring

pro

cedu

re:

1-Ch

eck t

hat L

ambd

a ox

igen

sens

or si

gnal

had

been

corre

ctly t

aken

;2-

Chec

k th

e ab

senc

e of

sho

rt-cir

cuit

betw

een

PREC

AT1

(or P

RECA

T2)

sign

alwi

re a

nd p

ositiv

e su

pply;

3-

Repla

ce S

eque

nt E

CU;

4-Re

place

PRE

CAT

1 (o

r PRE

CAT

2) la

mbd

a ox

igen

sens

or.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

r;2-

Star

t the

eng

ine a

nd ch

ange

ove

r fro

m p

etro

l to g

as m

ode;

3-Ve

rify t

he cr

edibi

lity o

f rea

d va

lues;

4-Dr

iving

in g

as m

ode

at le

ast f

or 1

0 km

with

med

ium lo

ad;

5-Ch

eck e

rrors

mem

ory.

Poss

ible

caus

es:

1-PR

ECAT

1 (o

r PRE

CAT

2) si

gnal

wire

is n

ot co

nnec

ted;

2-Se

nsor

settin

g is

not c

orre

ct;3-

Sequ

ent E

CU is

fault

y;4-

PREC

AT1

(or P

RECA

T2)

lam

bda

oxige

n se

nsor

is fa

ulty.

Repa

iring

pro

cedu

re:

1-Ch

eck t

hat L

ambd

a ox

igen

sens

or si

gnal

had

been

corre

ctly t

aken

;2-

Chec

k th

e PR

ECAT

1 (o

r PRE

CAT

2) s

ignal

wire

con

tinuit

y fro

m th

e se

nsor

(or

signa

l takin

g po

int) t

o th

e ga

s ECU

conn

ecto

r;3-

Chec

k th

e ab

senc

e of

sho

rt-cir

cuit

betw

een

PREC

AT1

(or P

RECA

T2)

sign

alwi

re a

nd n

egat

ive su

pply;

4-Ch

eck t

he s

enso

r set

ting;

5-Re

place

Seq

uent

ECU

;6-

Repla

ce P

RECA

T1

(or P

RECA

T2)

lam

bda

oxige

n se

nsor

.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

r;2-

Star

t the

eng

ine a

nd ch

ange

ove

r fro

m p

etro

l to g

as m

ode;

3-Ve

rify t

he cr

edibi

lity o

f rea

d va

lues;

4-Dr

iving

in g

as m

ode

at le

ast f

or 1

0 km

with

med

ium lo

ad;

5-Ch

eck e

rrors

mem

ory.

27/41

Dia

gnost

ic g

uid

e

5. DT

C P1

131 e

P11

51 P

RECA

T 1 L

ambd

a Oxig

en S

enso

r (gr

ound

) and

PRE

CAT

2 Lam

bda O

xigen

Sen

sor (

grou

nd)

It is

poss

ible

to d

iagno

se th

e fol

lowi

ng fa

ilure

s:No

t rea

sona

ble s

igna

l

Poss

ible

caus

es:

1-PR

ECAT

1 (o

r PRE

CAT

2) si

gnal

wire

is in

shor

t-circ

uit w

ith su

pply

wire

s;2-

PREC

AT1

(or P

RECA

T2)

sign

al wi

re is

not

conn

ecte

d;3-

Sens

or se

tting

is no

t cor

rect;

4-PR

ECAT

1 (o

r PRE

CAT

2) la

mbd

a ox

igen

sens

or is

fault

y.

Repa

iring

pro

cedu

re:

1-Ch

eck t

hat P

RECA

T1 (o

r PRE

CAT

2) g

roun

d ha

d be

en co

rrectl

y tak

en;

2-Ch

eck t

he a

bsen

ce o

f sho

rt-cir

cuit b

etwe

en th

e PR

ECAT

1 (o

r PRE

CAT

2) g

roun

d wi

re a

nd th

e su

pply

wire

s.3-

Chec

k the

PRE

CAT

1 (o

r PRE

CAT

2) g

roun

d wi

re co

ntinu

ity fr

om th

e se

nsor

(or s

ignal

takin

g po

int) t

o th

e ga

s ECU

conn

ecto

r;4-

Chec

k the

sen

sor s

ettin

g;5-

Repla

ce P

RECA

T1

(or P

RECA

T2)

lam

bda

oxige

n se

nsor

.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

r;2-

Star

t the

eng

ine a

nd ch

ange

ove

r fro

m p

etro

l to g

as m

ode;

3-Ve

rify t

he cr

edibi

lity o

f rea

d va

lues;

4-Dr

iving

in g

as m

ode

at le

ast f

or 1

0 km

with

med

ium lo

ad;

5-Ch

eck e

rrors

mem

ory.

28/41

Dia

gnost

ic g

uid

e

6. DT

C P1

180 G

as te

mpe

ratu

re se

nsor

(TGA

S)It

is po

ssib

le to

diag

nose

the f

ollo

wing

failu

res:

Sign

al va

lue u

nder

min

imum

thre

shol

dNo

t rea

sona

ble s

igna

lSi

gnal

valu

e ove

r max

imum

thre

shol

d

Poss

ible

caus

es:

1-TG

AS si

gnal

wire

is n

ot co

nnec

ted;

2-TG

AS se

nsor

is fa

ulty;

3-Se

quen

t ECU

is fa

ulty;

4-TG

AS s

ignal

wire

is in

sho

rt-cir

cuit

with

pos

itive

supp

ly.

Repa

iring

pro

cedu

re:

1-Ch

eck t

he T

GAS

conn

ecto

r;2-

Chec

k th

e ab

senc

e of

sho

rt-cir

cuit

betw

een

TGAS

signa

l wire

and

pos

itive

supp

ly;3-

Chec

k TG

AS s

ignal

wire

con

tinuit

y fro

m th

e se

n-so

r (or

sign

al ta

king

point

) to

the

gas E

CU co

nnec

-to

r;4-

Repla

ce T

GAS

sens

or;

5-Re

place

Seq

uent

ECU

.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

r;2-

Star

t the

eng

ine, c

hang

e ov

er to

gas

mod

e an

dve

rify c

redib

ility o

f rea

d va

lues;

3-Ch

eck e

rrors

mem

ory;

4-Re

pet t

his o

pera

tion

afte

r som

e m

inute

s in

idle

cond

itions

(abo

ut 1

0/15

min

) or a

fter d

rivin

g at

least

for 5

km.

Poss

ible

caus

es:

1-TG

AS s

ignal

wire

is in

sho

rt-cir

cuit

with

neg

ative

supp

ly;2-

TGAS

sens

oris

fault

y;3-

Sequ

ent E

CU is

fault

y.

Repa

iring

pro

cedu

re:

1-Ch

eck t

he T

GAS

conn

ecto

r;2-

Chec

k th

e ab

senc

e of

sho

rt-cir

cuit

betw

een

TGAS

signa

l wire

and

neg

ative

supp

ly;3-

Repla

ce T

GAS

sens

or;

4-Re

place

Seq

uent

ECU

.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

r;2-

Star

t the

eng

ine, c

hang

e ov

er to

gas

mod

e an

dve

rify c

redib

ility o

f rea

d va

lues;

3-Ch

eck e

rrors

mem

ory;

4-Re

pet t

his

oper

atio

n af

ter s

ome

min

utes

in id

leco

nditi

ons

(abo

ut 1

0/15

min

) or a

fter d

rivin

g at

least

for 5

km.

Poss

ible

caus

es:

1-Se

nsor

settin

g is

not c

orre

ct;2-

Erro

r due

to a

noth

er d

evice

failu

re (s

ee R

epair

ingpr

oced

ure)

;3-

TGAS

sens

oris

fault

y;4-

Sequ

ent E

CU is

fault

y.

Repa

iring

pro

cedu

re:

1-Ch

eck T

GAS

sens

or se

tting;

2-Ch

eck t

he in

stalle

d se

nsor

be

the

suita

ble o

ne;

3-If

you

have

a n

ot-re

ason

able

erro

r on

TGAS

sen

-so

r too

, foll

ow th

e sa

me

indica

tions

suit

able

for

erro

r P11

15;

4-If

you

have

an

erro

r on

the

sens

ors s

upply

tens

ion,

follo

w th

e sa

me

indi

catio

ns s

uita

ble

for e

rror

P160

8;5-

Repla

ce T

GAS

sens

or;

6 - R

eplac

e Se

quen

t ECU

.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

r;2-

Star

t the

eng

ine, c

hang

e ov

er to

gas

mod

e an

dve

rify c

redib

ility o

f rea

d va

lues;

3-Ch

eck e

rrors

mem

ory;

4-Re

pet t

his o

pera

tion

afte

r som

e m

inute

s in

idle

cond

itions

(abo

ut 1

0/15

min

) or a

fter d

rivin

g at

least

for 5

km.

29/41

Dia

gnost

ic g

uid

e

7. DT

C P1

190 (

1191

) P1 P

ress

ure S

enso

rIt

is po

ssib

le to

diag

nose

the f

ollo

wing

failu

res:

Sign

al va

lue u

nder

min

imum

thre

shol

dNo

t rea

sona

ble s

igna

lSi

gnal

valu

e ove

r max

imum

thre

shol

d

Poss

ible

caus

es:

1-P1

sign

al wi

re is

in s

hort-

circu

it wi

th n

egat

ive s

up-

ply;

2-P1

sign

al wi

re is

not

conn

eced

;3-

P1 p

ress

ure

sens

or is

fault

y;4-

Sequ

ent E

CU is

fault

y.

Repa

iring

pro

cedu

re:

1-Ch

eck P

1 se

nsor

conn

ecto

r;2-

Chec

k th

e ab

senc

e of

sho

rt-cir

cuit

betw

een

P1sig

nal w

ire a

nd n

egat

ive su

pply;

3-Ch

eck P

1 sig

nal w

ire co

ntinu

ity fr

om th

e se

nsor

toth

e ga

s ECU

conn

ecto

r;4-

Repla

ce P

1 se

nsor

;5-

Repla

ce S

eque

nt E

CU.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

r;2-

Star

t the

eng

ine, c

hang

e ov

er to

gas

mod

e an

dve

rify c

redib

ility o

f rea

d va

lues;

3-Ch

eck e

rrors

mem

ory.

Poss

ible

caus

es:

1-P1

sign

al wi

re is

in s

hort-

circu

it wi

th p

ositiv

e su

p-ply

;2-

P1 p

ress

ure

sens

or is

fault

y;3-

Sequ

ent E

CU is

fault

y.

Repa

iring

pro

cedu

re:

1-Ch

eck P

1 se

nsor

conn

ecto

r;2-

Chec

k th

e ab

senc

e of

sho

rt-cir

cuit

betw

een

P1sig

nal w

ire a

nd p

ositiv

e su

pply;

3-Re

place

P1

sens

or;

4-Re

place

Seq

uent

ECU

.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

r;2-

Star

t the

eng

ine, c

hang

e ov

er to

gas

mod

e an

dve

rify c

redib

ility o

f rea

d va

lues;

3-Ch

eck e

rrors

mem

ory.

Poss

ible

caus

es:

1-Se

nsor

settin

g is

not c

orre

ct;2-

Erro

r due

to a

noth

er d

evice

failu

re (s

ee R

epair

ingpr

oced

ure)

;3-

P1 p

ress

ure

sens

or is

fault

y;4-

Sequ

ent E

CU is

fault

y.

Repa

iring

pro

cedu

re:

1-Ch

eck P

1 se

nsor

settin

g;2-

Chec

k the

insta

lled

sens

or b

e th

e su

itable

one

;3-

If yo

u ha

ve a

not

-reas

onab

le er

ror o

n M

APpr

essu

-re

sen

sor t

oo, f

ollow

the

sam

e ind

icatio

ns s

uitab

lefo

r P11

05 e

rror;

4-If

you

have

an

erro

r on

the

TPS

sens

or to

o, fo

llow

the

sam

e ind

icatio

ns su

itable

for P

1120

erro

r;5-

If yo

u ha

ve a

n er

ror o

n th

e se

nsor

s sup

ply te

nsion

too,

follo

w th

e sa

me

indica

tions

suita

ble fo

r P16

08er

ror;

6-Re

place

P1

sens

or (a

nd/o

r P1b

is);

7-Re

place

Seq

uent

ECU

.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

r;2-

Star

t the

eng

ine, c

hang

e ov

er to

gas

mod

e an

dve

rify c

redib

ility o

f rea

d va

lues;

3-Ch

eck e

rrors

mem

ory.

30/41

Dia

gnost

ic g

uid

e

8. DT

C P1

201 P

1202

P12

03 P

1204

P12

05 P

1206

P12

07 P

1208

GAS

cylin

der i

njec

tor c

ontro

ls fro

m 1

to 8

It is

poss

ible

to d

iagno

se th

e fol

lowi

ng fa

ilure

s:Si

gnal

valu

e ove

r max

imum

thre

shol

dSi

gnal

valu

e und

er m

inim

um th

resh

old

Poss

ible

caus

es:

1-In

jecto

rs w

iring

is in

shor

t-circ

uit w

ith n

egat

ive su

pply;

2-In

jecto

rs w

iring

is no

t con

necte

d;3-

Sequ

ent E

CU is

fault

y;4-

Injec

tors

are

fault

y.

Repa

iring

pro

cedu

re:

1-Ch

eck i

njecto

rs co

nnec

tors

;2-

Chec

k the

abs

ence

of s

hort-

circu

it bet

ween

injec

tors

wirin

g an

d ne

gativ

e su

pply;

3-Ch

eck i

njecto

rs w

iring

cont

inuity

from

the

injec

tor c

onne

ctor t

o th

e ga

s ECU

con-

necto

r;4-

Chec

k inje

ctors

impe

danc

e (b

etwe

en 1

and

2 O

hm);

5-Re

place

Seq

uent

ECU

;6-

Repla

ce in

jecto

rs.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

rs;

2-Ta

ke e

ngine

at s

tead

y con

dition

unt

il the

pet

rol/g

as ch

ange

over

tem

pera

ture

;3-

Drive

in g

as m

ode

with

diffe

rent

s loa

d co

nditio

ns a

nd w

ith R

PM <

400

0 rp

m;

4-Ch

eck e

rrors

mem

ory.

Poss

ible

caus

es:

1-In

jecto

rs w

iring

is in

shor

t-circ

uit w

ith p

ositiv

e su

pply;

2-Se

quen

t ECU

is fa

ulty;

3-In

jecto

rs a

re fa

ulty.

Repa

iring

pro

cedu

re:

1-Ch

eck i

njecto

rs co

nnec

tors

;2-

Chec

k the

abs

ence

of s

hort-

circu

it bet

ween

injec

tors

wirin

g an

d po

sitive

supp

ly;3-

Chec

k inje

ctors

impe

danc

e (b

etwe

en 1

and

2 O

hm).;

4-Re

place

Seq

uent

ECU

;5-

Repla

ce in

jecto

rs.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

rs;

2-Ta

ke e

ngine

at s

tead

y con

dition

unt

il the

pet

rol/g

as ch

ange

over

tem

pera

ture

;3-

Drive

in g

as m

ode

with

diffe

rent

s loa

d co

nditio

ns a

nd w

ith R

PM <

400

0 rp

m;

4-Ch

eck e

rrors

mem

ory.

31/41

Dia

gnost

ic g

uid

e

9. DT

C P1

230 A

ctua

tors

relay

cont

rol

It is

poss

ible

to d

iagno

se th

e fol

lowi

ng fa

ilure

s:Si

gnal

valu

e und

er m

inim

um th

resh

old

Not r

easo

nabl

e sig

nal

Sign

al va

lue o

ver m

axim

um th

resh

old

Poss

ible

caus

es:

1-Ac

tuat

ors r

elay w

iring

is in

shor

t-circ

uit w

ith n

egat

i-ve

supp

ly;2-

Actu

ator

s rela

y wirin

g is

not c

onne

cted;

3-Re

lay is

fault

y;4-

Sequ

ent E

CU is

fault

y.

Repa

iring

pro

cedu

re:

1-Ch

eck a

ctuat

ors r

elay w

iring;

2-Ch

eck t

he a

bsen

ce o

f sho

rt-cir

cuit b

etwe

en a

ctua-

tors

relay

wirin

g an

d ne

gativ

e su

pply;

3-Ch

eck

actu

ator

s re

lay

wirin

g co

ntin

uity

from

its

conn

ecto

r to

the

gas E

CU o

ne;

4-Re

place

actu

ator

s rela

y;5-

Repla

ce S

eque

nt E

CU.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

rs;

2-St

art t

he e

ngine

and

chan

ge o

ver t

o ga

s mod

e;3-

Chec

k erro

rs m

emor

y.

Poss

ible

caus

es:

1-Ac

tuat

ors

relay

wirin

g is

in sh

ort-c

ircuit

with

pos

iti-ve

supp

ly;2-

Relay

is fa

ulty;

3-Se

quen

t ECU

is fa

ulty.

Repa

iring

pro

cedu

re:

1-Ch

eck a

ctuat

ors r

elay w

iring;

2-Ch

eck

the

abse

nce

of s

hort-

circu

it be

twee

n ac

tua-

tors

relay

wirin

g an

d po

sitive

supp

ly;3-

Repla

ce a

ctuat

ors r

elay;

4-Re

place

Seq

uent

ECU

.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

rs;

2-St

art t

he e

ngine

and

chan

ge o

ver t

o ga

s mod

e;3-

Chec

k erro

rs m

emor

y.

Poss

ible

caus

es:

1-Ac

tuat

ors r

elay w

iring

is in

shor

t-circ

uit w

ith n

egat

i-ve

supp

ly;2-

Actu

ator

s rela

y wirin

g is

not c

onne

cted;

3-Re

lay is

fault

y;4-

Sequ

ent E

CU is

fault

y.

Repa

iring

pro

cedu

re:

1-Ch

eck a

ctuat

ors r

elay w

iring;

2-Ch

eck t

he a

bsen

ce o

f sho

rt-cir

cuit b

etwe

en a

ctua-

tors

rela

y wi

ring

and

posi

tive

supp

ly o

r GND

(gro

und)

;3-

Chec

k inje

ctors

and

solen

oid va

lves c

onne

ctors

;4-

Repla

ce a

ctuat

ors r

elay;

5-Re

place

Seq

uent

ECU

.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

rs;

2-St

art t

he e

ngine

and

chan

ge o

ver t

o ga

s mod

e;3-

Chec

k erro

rs m

emor

y.

32/41

Dia

gnost

ic g

uid

e

10. D

TC P

1231

P12

32 P

1233

P12

34 G

AS S

olen

oid

valve

s [1..

4]It

is po

ssib

le to

diag

nose

the f

ollo

wing

failu

res:

Sign

al va

lue u

nder

min

imum

thre

shol

dSi

gnal

valu

e ove

r max

imum

thre

shol

d

Poss

ible

caus

es:

1-GA

S so

lenoid

valve

s wirin

g is

in sh

ort-c

ircuit

with

neg

ative

supp

ly;2-

GAS

solen

oid va

lves w

iring

is no

t con

necte

d;3-

Solen

oid va

lves a

re fa

ulty;

4-Se

quen

t ECU

is fa

ulty.

Repa

iring

pro

cedu

re:

1-Ch

eck G

AS so

lenoid

valve

s wirin

g;2-

Chec

k th

e ab

senc

e of

sho

rt-cir

cuit

betw

een

GAS

solen

oid v

alves

wirin

g an

dne

gativ

e su

pply;

3-Ch

eck

GAS

solen

oid v

alves

wirin

g co

ntinu

ity fr

om th

eir c

onne

ctor t

o th

e ga

sEC

U on

e;4-

Repla

ce G

AS so

lenoid

valve

s wirin

g;5-

Repla

ce G

AS so

lenoid

valve

;6-

Repla

ce S

eque

nt E

CU.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

rs;

2-St

art t

he e

ngine

and

chan

ge o

ver t

o ga

s mod

e;3-

Chec

k erro

rs m

emor

y.

Poss

ible

caus

es:

1-GA

S so

lenoid

valve

s wirin

g is

in sh

ort-c

ircuit

with

pos

itive

supp

ly;2-

Solen

oid va

lves a

re fa

ulty;

3-Se

quen

t ECU

is fa

ulty.

Repa

iring

pro

cedu

re:

1-Ch

eck G

AS so

lenoid

valve

s wirin

g;2-

Chec

k th

e ab

senc

e of

sho

rt-cir

cuit

betw

een

GAS

solen

oid v

alves

wirin

g an

dpo

sitive

supp

ly;3-

Chec

k GA

S so

lenoid

valv

es w

iring

cont

inuity

from

their

con

necto

r to

the

gas

ECU

one;

4-Re

place

GAS

solen

oid va

lves w

iring;

5-Re

place

Seq

uent

ECU

.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

rs;

2-St

art t

he e

ngine

and

chan

ge o

ver t

o ga

s mod

e;3-

Chec

k erro

rs m

emor

y.

33/41

Dia

gnost

ic g

uid

e

11. D

TC P

1335

RPM

or c

ranc

ksha

ft sig

nal

It is

poss

ible

to d

iagno

se th

e fol

lowi

ng fa

ilure

s:Si

gnal

not p

rese

ntNo

t rea

sona

ble s

igna

lSi

gnal

valu

e ove

r max

imum

thre

shol

d

Poss

ible

caus

es:

1-RP

M o

r cra

nksh

aft s

ignal

wire

is in

terru

pted

;2-

Sequ

ent E

CU is

fault

y;3-

Shor

t circ

uit to

ward

s pos

itive

or n

egat

ive;

4-RP

M o

r cra

nksh

aft s

ignal

wirin

g is

in sh

ort-c

ircuit

with

the

supp

lies.

Repa

iring

pro

cedu

re:

1-Ch

eck t

hat s

ignal

takin

g po

int is

corre

ct;2-

Chec

k RP

M o

r cra

nksh

aft s

ignal

wirin

g co

ntinu

ityfro

m th

e co

nnec

tor (

or ta

king

poin

t) to

the

gas

ECU

conn

ecto

r;3-

Repla

ce S

eque

nt E

CU.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

rs;

2-St

art t

he e

ngine

, cha

nge

over

to g

as m

ode

and

verif

y cre

dibilit

y of r

ead

value

s;3-

Chec

k erro

rs m

emor

y.

Poss

ible

caus

es:

1-Se

nsor

settin

g is

not c

orre

ct;2-

Sequ

ent E

CU is

fault

y.

Repa

iring

pro

cedu

re:

1-Ch

eck

settin

g pa

ram

eter

s an

d co

rrect

conn

ectio

nfo

r the

RPM

sign

al;2-

Chec

k RPM

wire

/wire

s con

tinuit

y fro

m th

e sig

nal o

rta

king

point

to th

e ga

s ECU

conn

ecto

r;3-

Repla

ce S

eque

nt E

CU.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

rs;

2-St

art t

he e

ngine

, cha

nge

over

to g

as m

ode

and

verif

y cre

dibilit

y of r

ead

value

s;3-

Chec

k erro

rs m

emor

y.

Poss

ible

caus

es:

1-Se

nsor

settin

g is

not c

orre

ct;2-

RPM

or c

rank

shaf

t sign

al wi

ring

is in

shor

t-circ

uitwi

th t

he su

pplie

s;3-

Sequ

ent E

CU is

fault

y.

Repa

iring

pro

cedu

re:

1-Ch

eck t

hat s

ignal

takin

g po

int is

corre

ct;2-

Chec

k the

RPM

or c

rank

shaf

t sign

al se

tting;

3-Ch

eck

the

abse

nce

of s

hort-

circu

it be

twee

n RP

Mor

cran

cksh

aft s

ignal

wirin

g an

d th

e su

pplie

s;4-

Repla

ce S

eque

nt E

CU.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

rs;

2-St

art t

he e

ngine

, cha

nge

over

to g

as m

ode

and

verif

y cre

dibilit

y of r

ead

value

s;3-

Chec

k erro

rs m

emor

y.

34/41

Dia

gnost

ic g

uid

e

12. D

TC P

1420

POS

TCAT

lam

bda o

xigen

sens

or (s

igna

l)It

is po

ssib

le to

diag

nose

the f

ollo

wing

failu

res:

Sign

al va

lue o

ver m

axim

um th

resh

old

Not r

easo

nabl

e sig

nal

Poss

ible

caus

es:

1-PO

STCA

Tsig

nal w

ire is

in sh

ort w

ith p

ositiv

e su

pply;

2-Se

quen

t ECU

is fa

ulty;

3-PO

STCA

Tse

nsor

is fa

ulty.

Repa

iring

pro

cedu

re:

1-Ch

eck l

ambd

a ox

ygen

sens

or si

gnal

had

been

corre

ctly t

aken

;2-

Chec

k th

e ab

senc

e of

sho

rt-cir

cuit

betw

een

POST

CAT

signa

l wire

and

pos

itive

supp

ly;3-

Repla

ce S

eque

nt E

CU;

4-Re

place

POS

TCAT

sens

or.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

r;2-

Star

t the

eng

ine a

nd ch

ange

ove

r fro

m p

etro

l to g

as m

ode;

3-Ve

rify t

he cr

edibi

lity o

f rea

d va

lues;

4-Dr

iving

in g

as m

ode

at le

ast f

or 1

0 km

with

med

ium lo

ad;

5-Ch

eck e

rrors

mem

ory.

Poss

ible

caus

es:

1-PO

STCA

Tsig

nal w

ire is

not

conn

ecte

d;2-

Sens

or se

tting

is no

t cor

rect;

3-Se

quen

t ECU

is fa

ulty;

4-PO

STCA

Tse

nsor

is fa

ulty.

Repa

iring

pro

cedu

re:

1-Ch

eck l

ambd

a ox

ygen

sens

or si

gnal

had

been

corre

ctly t

aken

;2-

Chec

k POS

TCAT

signa

l wire

cont

inuity

from

its co

nnec

tor (

or si

gnal

takin

g po

int)

to g

as E

CU co

llecto

r;3-

Chec

k sen

sor s

ettin

g;4-

Repla

ce S

eque

nt E

CU;

5-Re

place

POS

TCAT

sens

or.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

r;2-

Star

t the

eng

ine a

nd ch

ange

ove

r fro

m p

etro

l to g

as m

ode;

3-Ve

rify t

he cr

edibi

lity o

f rea

d va

lues;

4-Dr

iving

in g

as m

ode

at le

ast f

or 1

0 km

with

med

ium lo

ad;

5-Ch

eck e

rrors

mem

ory.

35/41

Dia

gnost

ic g

uid

e

13. D

TC P

1460

Gas

leve

l sen

sor

It is

poss

ible

to d

iagno

se th

e fol

lowi

ng fa

ilure

s:Si

gnal

valu

e ove

r max

imum

thre

shol

dSi

gnal

valu

e und

er m

inim

um th

resh

old

Poss

ible

caus

es:

1-Le

vel s

enso

r wirin

g is

inter

rupt

ed;

2-Le

vel s

enso

r wirin

g is

in sh

ort-c

ircuit

with

pos

itive

supp

ly;3-

Sens

or se

tting

is no

t cor

rect;

4-Le

vel s

enso

r is f

aulty

;5-

Erro

r due

to a

noth

er d

evice

failu

re (s

ee R

epair

ing p

roce

dure

);6-

Sequ

ent E

CU is

fault

y.

Repa

iring

pro

cedu

re:

1-Ch

eck l

evel

sens

or co

nnec

tor;

2-Ch

eck t

he a

bsen

ce o

f sho

rt-cir

cuit b

etwe

en le

vel s

enso

r wirin

g an

d po

sitive

bat

-te

ry;

3-Ch

eck l

evel

sens

or w

iring

cont

inuity

up

to th

e ga

s ECU

conn

ecto

r;4-

Chec

k lev

el se

nsor

settin

g;5-

Chec

k BRC

sens

or in

stalle

d be

the

suita

ble o

ne;

6-If

you

have

an

erro

r on

the

sens

or s

upply

tens

ion, f

ollow

the

sam

e ind

icatio

nssu

itable

for e

rror P

1608

;7-

Repla

ce le

vel s

enso

r.8-

Repla

ce S

eque

nt E

CU.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

rs;

2-St

art t

he e

ngine

, cha

nge

over

to g

as m

ode

and

verif

y cre

dibilit

y of r

ead

value

s;3-

Chec

k erro

rs m

emor

y.

Poss

ible

caus

es:

1-Le

vel s

enso

r wirin

g is

in sh

ort-c

ircuit

with

the

grou

nd;

2-Se

nsor

settin

g is

not c

orre

ct;3-

Leve

l sen

sor i

s fau

lty;

4-Er

ror d

ue to

ano

ther

dev

ice fa

ilure

(see

Rep

airing

pro

cedu

re);

5-Se

quen

t ECU

is fa

ulty.

Repa

iring

pro

cedu

re:

1-Ch

eck l

evel

sens

or co

nnec

tor;

2-Ch

eck t

he a

bsen

ce o

f sho

rt-cir

cuit b

etwe

en le

vel s

enso

r wirin

g an

d gr

ound

;3-

Chec

k lev

el se

nsor

wirin

g co

ntinu

ity u

p to

the

gas E

CU co

nnec

tor;

4-Ch

eck l

evel

sens

or se

tting;

5-Ch

eck B

RC se

nsor

insta

lled

be th

e su

itable

one

;6-

If yo

u ha

ve a

n er

ror o

n th

e se

nsor

sup

ply te

nsion

, foll

ow th

e sa

me

indica

tions

suita

ble fo

r erro

r P16

08;

7-Re

place

leve

l sen

sor.

8-Re

place

Seq

uent

ECU

.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

rs;

2-St

art t

he e

ngine

, cha

nge

over

to g

as m

ode

and

verif

y cre

dibilit

y of r

ead

value

s;3-

Chec

k erro

rs m

emor

y.

36/41

Dia

gnost

ic g

uid

e

14. D

TC P

1560

Bat

tery

volta

geIt

is po

ssib

le to

diag

nose

the f

ollo

wing

failu

res:

Sign

al va

lue o

ver m

axim

um th

resh

old

Sign

al va

lue u

nder

min

imum

thre

shol

d

Poss

ible

caus

es:

1-Ba

ttery

volta

ge is

too

high

(> 1

6V);

2-Ba

ttery

volta

ge h

as b

een

take

n in

a wr

ong

point

;3-

Grou

nd re

fere

nce

has b

een

take

n in

a wr

ong

point

;4-

Sequ

ent E

CU is

fault

y.

Repa

iring

pro

cedu

re:

1-Ch

eck b

atte

ry su

pply

wirin

g;2-

Chec

k su

pply

wirin

g co

ntinu

ity (p

ositiv

e ba

ttery

and

gro

und)

from

the

takin

gpo

int to

the

gas E

CU co

nnec

tor;

3-Ch

eck b

atte

ry vo

ltage

with

a vo

ltmet

er;

4-Re

place

Seq

uent

ECU

.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

rs;

2-St

art t

he e

ngine

, cha

nge

over

to g

as m

ode

and

verif

y cre

dibilit

y of r

ead

value

s;3-

Chec

k erro

rs m

emor

y.

Poss

ible

caus

es:

1-Ba

ttery

volta

ge is

too

low (<

6V)

;2-

Batte

ry vo

ltage

has

bee

n ta

ken

in a

wron

g po

int;

3-Gr

ound

refe

renc

e ha

s bee

n ta

ken

in a

wron

g po

int;

4-Se

quen

t ECU

is fa

ulty.

Repa

iring

pro

cedu

re:

1-Ch

eck b

atte

ry su

pply

wirin

g;2-

Chec

k su

pply

wirin

g co

ntinu

ity (p

ositiv

e ba

ttery

and

gro

und)

from

the

takin

gpo

int to

the

gas E

CU co

nnec

tor;

3-Ch

eck b

atte

ry vo

ltage

with

a vo

ltmet

er;;

4-Re

place

Seq

uent

ECU

.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

rs;

2-St

art t

he e

ngine

, cha

nge

over

to g

as m

ode

and

verif

y cre

dibilit

y of r

ead

value

s;3-

Chec

k erro

rs m

emor

y.

37/41

Dia

gnost

ic g

uid

e

15. D

TC P

1608

Sen

sors

supp

ly te

nsio

nIt

is po

ssib

le to

diag

nose

the f

ollo

wing

failu

res:

Sign

al va

lue o

ver m

axim

um th

resh

old

Sign

al va

lue u

nder

min

imum

thre

shol

d

Poss

ible

caus

es:

1-Se

nsor

s sup

ply te

nsion

is to

o hig

h (>

6V)

;2-

Sens

ors

supp

ly wi

ring

is in

shor

t-circ

uit w

ith p

ositiv

e ba

ttery

(it i

nvolv

es a

n er

ror

reco

rding

on

ever

y sen

sor);

3-Se

quen

t ECU

is fa

ulty (

it inv

olves

an

erro

r rec

ordin

g on

eve

ry se

nsor

).

Repa

iring

pro

cedu

re:

1-Ch

eck s

enso

rs su

pply

tens

ion w

iring;

2-Ch

eck s

enso

rs su

pply

tens

ion w

iring

from

gas

ECU

to th

e dif

fere

nt se

nsor

s con

-ne

ctors

;3-

Chec

k gas

ECU

fuse

s con

tinuit

y;4-

Chec

k sen

sors

supp

ly te

nsion

com

ing o

ut fr

om th

e ga

s ECU

with

a vo

ltmet

er;

5-Re

place

Seq

uent

ECU

.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

rs;

2-St

art t

he e

ngine

, cha

nge

over

to g

as m

ode

and

verif

y cre

dibilit

y of r

ead

value

s;3-

Chec

k erro

rs m

emor

y.

Poss

ible

caus

es:

1-Se

nsor

s sup

ply te

nsion

is to

o low

(< 4

V);

2-Se

nsor

s su

pply

wirin

g is

in sh

ort-c

ircuit

with

gro

und

(it in

volve

s an

erro

r rec

or-

ding

on e

very

sens

or);

3-Se

quen

t ECU

is fa

ulty (

it inv

olves

an

erro

r rec

ordin

g on

eve

ry se

nsor

).

Repa

iring

pro

cedu

re:

1-Ch

eck s

enso

rs su

pply

tens

ion w

iring;

2-Ch

eck s

enso

rs su

pply

tens

ion w

iring

from

gas

ECU

to th

e dif

fere

nt se

nsor

s con

-ne

ctors

;3-

Chec

k gas

ECU

fuse

s con

tinuit

y;4-

Chec

k sen

sors

supp

ly te

nsion

com

ing o

ut fr

om th

e ga

s ECU

with

a vo

ltmet

er;

5-Re

place

Seq

uent

ECU

.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

rs;

2-St

art t

he e

ngine

, cha

nge

over

to g

as m

ode

and

verif

y cre

dibilit

y of r

ead

value

s;3-

Chec

k erro

rs m

emor

y.

38/41

Dia

gnost

ic g

uid

e

16. D

TC P

1650

Gas

/pet

rol c

hang

eove

r swi

tch

signa

lIt

is po

ssib

le to

diag

nose

the f

ollo

wing

failu

res:

Sign

al va

lue o

ver m

axim

um th

resh

old

Not r

easo

nabl

e sig

nal

Poss

ible

caus

es:

1-Ch

ange

over

switc

h sig

nal w

ire is

in sh

ort-c

ircuit

with

neg

ative

supp

ly;2-

Chan

geov

er sw

itch

signa

l wire

is n

ot co

nnec

ted;

3-Ga

s/Pet

rol c

hang

eove

r swi

tch is

fault

y;4-

Sequ

ent E

CU is

fault

y;5-

Erro

r due

to a

noth

er d

evice

failu

re (s

ee R

epair

ing p

roce

dure

).

Repa

iring

pro

cedu

re:

1-Ch

eck g

as/p

etro

l cha

ngeo

ver s

witch

conn

ecto

r.2-

Chec

k the

abs

ence

of s

hort-

circu

its b

etwe

en ch

ange

over

switc

h wi

re a

nd su

pply

wire

s;3-

Chec

k ch

ange

over

swi

tch w

ire c

ontin

uity

from

its

conn

ecto

r up

to th

e ga

s EC

Uco

nnec

tor;

4-If

you

have

an

erro

r on

the

sens

or s

upply

tens

ion, f

ollow

the

sam

e ind

icatio

nssu

itable

for e

rror P

1608

;5-

Repla

ce g

as/p

etro

l cha

ngeo

ver s

witch

.6-

Repla

ce S

eque

nt E

CU.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

r;2-

Star

t the

eng

ine a

nd ch

ange

ove

r to

gas m

ode;

3-Ch

eck e

rrors

mem

ory.

Poss

ible

caus

es:

1-Ch

ange

over

switc

h sig

nal w

ire is

in sh

ort-c

ircuit

with

supp

ly;2-

Chan

geov

er sw

itch

signa

l wire

is n

ot co

nnec

ted;

3-Ga

s/Pet

rol c

hang

eove

r swi

tch is

fault

y;4-

Sequ

ent E

CU is

fault

y;5-

Erro

r due

to a

noth

er d

evice

failu

re (s

ee R

epair

ing p

roce

dure

).

Repa

iring

pro

cedu

re:

1-Ch

eck

the

abse

nce

of s

hort-

circu

it be

twee

n ch

ange

over

swi

tch w

iring

and

sup-

ply;

2-Ch

eck c

hang

eove

r swi

tch w

iring

cont

inuity

;3-

Chec

k cha

ngeo

ver s

witch

wirin

g co

nnec

tor;

4-Re

place

chan

geov

er sw

itch.

Oper

atio

n ch

eck:

1-Er

ase

the

erro

r;2-

Star

t the

eng

ine a

nd ch

ange

ove

r to

gas m

ode;

3-Ch

eck e

rrors

mem

ory.

DIAGNOSTIC GUIDE

39/41

7. NOMENCLATURE

Absolute pressure: Pressure measured with reference (value=0) to the perfect vacuum.Battery positive: The pole with higher electric potential of the vehicle battery. Normally it has a voltagebetween 8 and 16V compared to the ground (see “Ground”).Bottom Feed: See “Top Feed”. Particular type of injector, in which path fuel only involves the injector bottompart.CAN Bus: Communication system between ECUs and devices installed on a vehicle.Cartography: See “Mapping”Catalyst: Device installed on the exhaust duct in order to reduce the polluting emissions.Changeover switch: It is the device situated in the passenger compartment which allows to choose the fueltype (gas or petrol).Changeover to Petrol at idle: Strategy which allows the vehicle re-changeover from Gas to Petrol under apredefined RPM threshold. Petrol stay is not definitive but it has two outlet threshold, one on the time and oneon the RPM, that you can both set up from interface.Changeover to Petrol in Cut-Off: Strategy that allows to make petrol injections every time it go out from theCut-Off condition, both for return to idle and for a tip-in. From the program you can set up the RPM thresholduseful to have a valid changeover condition, and the numbers of petrol injections made by the system beforethe automatic re-changeover to gas.Close-Loop: Engine working condition where petrol ECU modifies the carburation according to the signalread by the Lambda oxigen sensor. In this condition ECU searches for the stoichiometry and, because of a notcorrect gas mapping, it should modify the self-mapping parameters and therefore turns the CHECK indicatoron.Cold strategy: Strategy which allows the gas calibration correction when the vehicle is still cold. You canmodify from interface both the Flow correction and the temperature spread in which you can correct the cali-bration.Connector: Device which connects wirings parts with other wiring parts or with electric devices.Crankshaft (sensor): Sensor installed near a gearwheel supportive with the drive shaft; it produces an elec-tric signal that represents the drive shaft position.Cut-Off: Particular engine working condition where injectors don’t supply fuel to the cylinder, so that theyintake pure air. Normally, you are in cut-off during a tip-out, with possible vehicle deceleration (engine brake),starting from rpm not too low.Delta-P: Value calculated from the difference between the P1 (pressure inside gas rail) and the MAP (pressu-re inside the manifold). This parameter allows to recognize the failed supply condition. If Delta-P value decrea-ses under the Delta-P Minimum set up in Changeover, vehicle re-changes over to petrol for end of gas.Diagnostic: Identification process of cause or nature of a problem, a failure, or of a particular condition /situa-tion to find and indicate as wrong working.Duty Cycle: In a rectangular wave-shape is the proportion between the high level duration and the wave-shape period. In formulas, if Ton is the high level duration and Toff is the low level duration, then Tp = Ton +Toff is the period and DC = Ton / Tp = Ton / (Ton+Toff) is the Duty Cycle.ECU: It is the Electronic Control Unit of the engine or of the gas carburation.EOBD: See “OBD”. European On Board Diagnostics. European implementation of OBD systems, regulatedfrom institutions as ISO.Flow: Physical measure that defines the fluid quantity passing through a specific section in a time unit. Massflow defines, for instance, how many grams of a fluid pass through a specific section in a second.Fuel Injectors: See “Rail” It is the element on which injectors are installed; thanks to this element, the gas atthe required pressure can be opportunely supplied at every injector inlet.

DIAGNOSTIC GUIDE

40/41

Gas Injection Strategy in Cut-Off: Only for Sequent24. Strategy which allows the gas injectors advance ope-ning while vehicle is still in Cut-Off condition. You can set up RPM threshold and Gas Injection Time from inter-face. Ex. 3 ms under the 2000 rpm.Ground: Reference electric potential (relative tension amounting to zero Volt). It is also the mass of wires andelectric conductor connected to this potential. Ground potential is on the negative pole (that’s to say at thelower electric potential) of the vehicle battery, so that it’s called battery ground too.Injector: Device which supplies accurate measured quantities of fuel in pressure, injecting them in the intakemanifold.K line: Communication line of engine ECU towards the external diagnostic instrument, according to ISO 9141e ISO 14230 regulations.Lambda Oxigen Sensor: Sensor measuring the oxigen concentration in the exhaust gas. Thanks to this sen-sor the ECU determines if air/fuel mix is too rich or too poor in fuel, permitting the system closed loopworking.LED: Light Emitting Diode. Semiconductor electronic device that can glow if crossed by electric current.LPG: Liquefied Petroleum Gas. It is a fuel coming from petroleum distillation, essentially made up of Butaneand Propane in variable proportions. You can find it in gaseous state at ambient temperature and pressure,whereas it is liquid inside the tank.Magnetic loop: Magnetic flow path, usually made of iron or other iron-magnetic material. It is part of an elec-tromagnetic device (solenoid valve, injector, electric engine, and so on).Mapping/Map: It is the mass of data that defines fuel quantity to dose in accordance with the engine workingconditions.MAP: (Manifold Absolute Pressure) Absolute pressure of the engine intake manifold (see Absolute pressure).It indicates the relative sensor too.Multivalve: Device situated on the tank that performs different functions, controlling the tank filling, the fuellevel, the security protection,and so on.OBD (On Board Diagnostics): See also “Diagnostic”. Monitoring system of all or some inlet and ECU signalcontrol. If it finds one or more signals over the predefined threshold, it informs and records thesystem/systems bad working.Open-Loop: Engine working condition where petrol ECU doesn’t consider anymore the signal read byLambda oxigen sensor. You normally have this condition when you ask to the engine a complete power. ECUenriches carburation in full load searching for the better performance and in order to decrease temperatureinside the catalyst.OR: (O-Ring) Gasket made up of a rubber ring.PC: Personal ComputerPeak & Hold (piloting): See also “Piloting”. Particular injectors piloting that supplies to the coil early a biggercurrent in the opening phase, so that it can reduces the injector opening time (peak); then current goes downto a value enough to maintain the injector open (hold).Piloting: It shows action and way with which electric actuators are controlled by the ECU or other electricdevice, through power electric signals.Positive under key: Tension or electric knot situated before the switch activated by the vehicle ignition key.Normally it has a low potential; it reaches the battery positive potential when you turn the key off.POSTCAT Lambda Oxigen Sensor: Lambda Oxigen Sensor situated after the catalyst.PRECAT Lambda Oxigen Sensor: Lambda Oxigen Sensor situated before the catalyst.Pressure differential: Pressure difference between two zones, for instance between the intake manifold andthe atmospheric pressure.Relative pressure: Pressure measured with reference (value=0) to the atmospheric pressure.Relay: Electromechanic device that can open or close one or more electric contact after appropriate electricpiloting.RPM: Acronym for revolutions per minute. It usually indicates drive shaft rotation speed.RPM Decrease Strategy: Strategy which allows to modify the mapping in condition of return to idle. You canset up Flow correction and strategy work time from interface.

DIAGNOSTIC GUIDE

41/41

Sensor: Device measuring a physical quantity value as temperature, pressure, speed, and it converts it inelectric signal useful to the ECU or to another electric device.Sequential injection: Injection management system of a modern vehicle with fuel electronic injection; herethe injection phase of every cylinder starts and ends according to indipendent times for everyone of them. Theengine ECU verifies these times and correlates them with the cylinder phase and position.Solenoid valve: Electromechanic device that stops a fluid flow. In our case, this device stops gas flow whenit’s not supplied, otherwise it lets the gas flow.Three-way catalyst: Catalyst that reduces the HC, CO and NOx values.Throttle Valve: Valve that regulates the air flow intook from the engine. Normally is controlled from the accele-rator pedal but nowadays it is controlled directly from the petrol ECU more and more.TonG: Gas Injection Time. It shows how long the gas injector stays open in order to supply the required gasflow..TonMinGas: Parameter situated in Map Refinement/Other. It shows the TonP at idle in gas mode. The systemconsiders this value in order to recognize its work mode during the map control: at idle (TonP = TonMinGas) orrunning (TonP > TonMinGas). Value is calculated automatically during the self-mapping, but you can correct itafter checking the mapping at idle.TonP: Petrol Injection Time. It shows how long the petrol injector stays open in order to supply the right cali-bration.Top Feed: See “Bottom Feed”. Particular type of injector, in which path fuel passes through the whole lenghtof the injector in an axial way, arriving from the top and being injected in the low part of the device.TPS: Throttle Valve Position Sensor. It supplies an electric signal that shows the throttle valve opening (see“Throttle Valve”).Wiring: It is the mass of wires going from the ECU connector to all the other system wiring points.

ta01z036i gas serviceraspinovka).… · difference between second rail pressure and manifold...

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