23 · Diagnostics

Engine does not switch to gas

Make: Fiat
Model: Ducato Factory Service Manual
Year: 2002–2006
Section: Engine › Engine does not switch to gas

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Fault diagnosisEngine does not switch to gas

ENGINE DOES NOT SWITCH TO GAS

2.0 16V · BIPOWER

The engine starts normally in petrol mode but does not then switch to methane mode.

STEP	OPERATIONS TO BE CARRIED OUT	TEST RESULTS
0	PRELIMINARY CHECKS	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check, first, for the presence of METHANE in the tank by checking methane pressure at the reduction unit intake	Move on to Step 1	Pressure lower than 15 bar and methane level therefore too low	Restore correct methane level
1	CHECK USING DIAGNOSTIC EQUIPMENT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Connect the diagnostic equipment to the diagnostic connector and check the following at the petrol and METHANE engine management unit, in the errors ambient: no errors in the petrol and METHANE management control unit	Move on to Step 2	Error detected in the petrol engine management unit	Continue following the instructions for the diagnostic equipment
			Error detected in the METHANE engine management unit	Continue following the instructions for the diagnostic equipment
			No communication between the petrol engine management unit and METHANE engine management unit	Restore connection between petrol and METHANE control unit See E5032 METHANE ENGINE ELECTRONIC MANAGEMENT
			METHANE control unit not connected to earth	Restore earth connection See E5032 METHANE ENGINE ELECTRONIC MANAGEMENT
2	CHECK METHANE INJECTORS	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check methane injectors are operating correctly See Test 1058A GAS CIRCUIT MULTI POINT INJECTION	Move on to Step 3	Methane injectors defective	Replace the injectors Op. 1058A68 SET OF CNG INJECTION SYSTEM INJECTORS - R R WITH CNG MANIFOLD PIPE REMOVED INCLUDES GASKET REPLACEMENT
		Move on to Step 3	Injector control relay defective	Replace the relay
3	CHECK METHANE/PETROL SELECTION BUTTON	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Keeping the Examiner diagnostic equipment connected to the diagnostic connector check the following at the engine control unit, in the parameters ambient: correct operation of the METHANE/Petrol selector Check operation of the METHANE/Petrol selector See Test 1058O CNG SUPPLY TESTS	Move on to Step 4	METHANE/PETROL selector defective	Replace the switch Op. 1058A20 CNG/METHANE SWITCH - R.R.
			Wiring broken	Restore wiring See E5032 METHANE ENGINE ELECTRONIC MANAGEMENT
			Selector power supply interrupted	Restore wiring continuity See E5032 METHANE ENGINE ELECTRONIC MANAGEMENT
			Methane control unit defective	Replace METHANE control unit Op. 1058A80 CNG INJECTION UNIT CONTROL UNIT - R R
4	CHECK METHANEN PRESSURE SIGNAL	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check the following, in order: correct power supply to methane pressrue sensor; the correct voltage signal for the methane level sensor to the methane control unit, by carrying out Test 1058AA See Test 1058A GAS CIRCUIT MULTI POINT INJECTION	Move on to Step 5	Methane pressure sensor power supply incorrect	Restore correct power supply See E5032 METHANE ENGINE ELECTRONIC MANAGEMENT
		Move on to Step 5	Pressure sensor defective	Replace pressure sensor Op. 1058A44 CNG/FUEL SWITCH - R R
5	CHECK CAN LINE CONNECTING ENGINE MANAGEMENT CONTROL UNIT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check continuity/insulation of CAN line connecting petrol engine control unit and methane engine management unit See E5032 METHANE ENGINE ELECTRONIC MANAGEMENT	End of diagnosis	CAN line interrupted	Restore continuity See E5032 METHANE ENGINE ELECTRONIC MANAGEMENT
			CAN line short-circuited	Restore insulation See E5032 METHANE ENGINE ELECTRONIC MANAGEMENT
			Methane control unit defective	Replace control unit Op. 1058A80 CNG INJECTION UNIT CONTROL UNIT - R R

2.0 16V · GPL

The engine starts normally in petrol mode but does not then switch to GAS mode.

STEP	OPERATIONS TO BE CARRIED OUT	TEST RESULTS
0	PRELIMINARY CHECKS	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check, first of all, that there is LPG in the tank	Move on to Step 1	LPG level low	Restore correct LPG level
1	CHECK USING DIAGNOSTIC EQUIPMENT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Connect the diagnostic equipment to the diagnostic connector and check the following at the petrol and LPG engine management unit: in the errors ambient no errors in the petrol and LPG management control units; in the parameters ambient, the plausibility of all the parameters	Move on to Step 2	Error detected in the petrol engine management unit	Continue following the instructions for the diagnostic equipment
			Error detected in the LPG engine management unit	Continue following the instructions for the diagnostic equipment
			No communication between the petrol engine management unit and LPG engine management unit	Restore connection between petrol and LPG control unit See E5031 LPG FUEL SYSTEM ELECTRONIC MANAGEMENT
			LPG control unit not connected to earth	Restore earth connection See E5031 LPG FUEL SYSTEM ELECTRONIC MANAGEMENT
			LPG pressure more than or equal to 20 bar	Move on to Step 6
2	GAS/PETROL SELECTOR CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Keeping the Examiner diagnostic equipment connected to the diagnostic connector check the following at the engine control unit, in the parameters ambient: correct operation of the GAS/Petrol selector. Check the operation of the GAS/Petrol selector by carrying out Test 1057OA See Test 1057O LGP SUPPLY TESTS	Move on to Step 3	GAS/PETROL selector defective	Replace the selector
			Wiring broken	Restore wiring See E5031 LPG FUEL SYSTEM ELECTRONIC MANAGEMENT
			Selector power supply interrupted	Restore wiring continuity See E5031 LPG FUEL SYSTEM ELECTRONIC MANAGEMENT
			LPG control unit defective	Replace LPG control unit
3	CHECK CAN LINE CONNECTING ENGINE MANAGEMENT CONTROL UNIT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check continuity/insulation of CAN line connecting petrol engine control unit and LPG engine management unit See E5031 LPG FUEL SYSTEM ELECTRONIC MANAGEMENT	Move on to Step 4	CAN line interrupted	Restore continuity See E5031 LPG FUEL SYSTEM ELECTRONIC MANAGEMENT
		Move on to Step 4	CAN line short-circuited	Restore insulation See E5031 LPG FUEL SYSTEM ELECTRONIC MANAGEMENT
4	LPG LEVEL SENSOR CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check the following, in order: correct power supply to LPG level sensor; the correct operation of the LPG level sensor, by carrying out Test 1043AE See Test 1043A GPL TANK	Move on to Step 5	LPG level sensor power supply not correct	Restore correct power supply See E5031 LPG FUEL SYSTEM ELECTRONIC MANAGEMENT
		Move on to Step 5	LPG level sensor defective	Replace the LPG level sensor
5	CHECK LPG PRESSURE	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check the following, in order: the correct operation of the LPG pressure sensor, by carrying out Test 1043BB; the correct operation of the LPG return solenoid valve, by carrying out Test 1043BC; the correct operation of the LPG pump, by carrying out Test 1043AA See Test 1043B GPL FUEL CIRCUIT PIPES See Test 1043A GPL TANK	Move on to Step 6	Pressure sensor defective	Replace the sensor
			Return solenoid defective	Replace the solenoid valve
			LPG pump defective	Replace the LPG pump
6	CHECK ON TANK FILLER RESTRICTER VALVE AND LPG LEVEL SENSOR FLOAT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Disconnect the LPG tank, drain it, send it to the authorized service centre and check: the correct operation of the tank filling restricter valve, by carrying out Test 1043AF; the correct operation of the LPG level sensor, by carrying out Test 1043AE See Test 1043A GPL TANK	End of diagnosis	Filler restricter valve faulty	Replace the tank filler restricter valve
		End of diagnosis	Level sensor float defective	Replace the sensor

‹ Prev Engine cuts out whilst driving Next › Side lights/no. plate lights not working

Parts & tools for this job For 2002 Fiat Ducato

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