Page 84 of 107

17C-84
MR-372-J84-17C000$708.mif
V2
17C
GAS INJECTION
Fault finding - Interpretation of parameters
PR003
PRESSURE DIFFERENCE: LPG/ MANIFOLD
IMPORTANT
For an operation on a component of the LPG supply circuit, consult the safety instructions (see 17D,
Gas injection, Introduction, Safety instructions for all operations).
NOTESThere must be no present or stored faults.
Engine running in LPG mode.
Check that the pressure difference is 800 mbar.
Check the consistency in pressure difference using parameters PR001 Manifold pressure, PR003 Pressure
difference: LPG/manifold and PR112 LPG pressure downstream of expansion valve and ensure that
PR003 = PR112 - PR001.
If the fault is still present, manipulate the wiring harness between the manifold pressure sensor and the LPG
pressure/temperature sensor in order to produce a change in status.
Check the connection and condition of the manifold pressure sensor and the LPG pressure / temperature
sensor, and its connections.
If necessary, repair or replace the connector.
If the pressure difference is still inconsistent, apply the interpretation of fault DF031 LPG pressure downstream
of expansion valve.
If the fault is still present, replace the LPG pressure/temperature sensor (see MR 364 Mechanical, 17D,
LPG injection).
If the fault is still present, check the manifold pressure sensor by testing the Petrol computer (see 17B,
Petrol injection, Interpretation of faults).
If the fault is still present, contact the Techline.
AFTER REPAIRFollow the instructions to confirm repair.
GAZ3000_V08_PR003 / GAZ3000_V10_PR003
LPG 3000
Program No.
Vdiag No: 08/10
MR-372-J84-17C000$708.mif
Page 98 of 107
17C-98
MR-372-J84-17C000$885.mif
V2
17C
GAS INJECTION
Fault finding - Customer complaints
NOTESOnly check the customer complaint after performing a complete check with the fault
finding tool.
IMPORTANT
For any operation on a component of the LPG supply circuit, consult the safety
instructions (see 17D, LPG injection, Introduction).
NO DIALOGUE WITH THE COMPUTER ALP 1
LPG GAUGE FAULTSALP 2
THE ENGINE STALLS WHEN SWITCHED TO LPG MODE ALP 3
IDLE SPEED FAULTSALP 4
FAULTS WHILE DRIVINGALP 5
LPG LEAK
LPG LEAK WHEN REFILLING
THE TANKALP 6
LPG 3000
Program No.
Vdiag No: 08/10
MR-372-J84-17C000$885.mif
Page 100 of 107

17C-100
MR-372-J84-17C000$944.mif
V2
GAS INJECTION
Fault finding - Fault finding chart (ALP)
LPG 3000
Program No: AB
Vdiag No: 08/10
17C
ALP 2 LPG sender fault
For Mégane II
IMPORTANT
When carrying out an operation on an LPG supply circuit component, consult the safety instructions
(see 17D, Gas injection, Introduction, Safety instructions for all operations).
NOTESCheck that there is LPG in the tank.
Disconnect the LPG tank sender connector and check the voltage of the sensor signal using parameter
PR007 LPG tank sender signal voltage.
Replace the sensor if the signal voltage is not approximately:4.8 V tank full
1 V in reserve
0.2 V tank empty
Check for earth on track C (for Mégane 2) of the LPG tank connector.
Repair if necessary.
Check the insulation in relation to earth and the continuity and the absence of interference resistance on
the connection between:
For Mégane 2:
LPG computer track B1 track B of the LPG tank sender
If the fault is still present, check the intermediate connectors (R2 track 36 and R34 track 34 for Mégane 2).
Repair if necessary.
If the fault is still present, check the LPG tank pressure sensor (see MR 364 Mechanical, 17D, LPG injection).
AFTER REPAIRCheck using the diagnostic tool.
GAZ3000_V08_ALP2 / GAZ3000_V10_ALP2
Page 101 of 107

17C-101
MR-372-J84-17C000$944.mif
V2
GAS INJECTION
Fault finding - Fault finding chart (ALP)
LPG 3000
Program No: AB
Vdiag No: 08/10
17C
ALP 2
CONTINUED 1
For Logan
IMPORTANT
When carrying out an operation on an LPG supply circuit component, consult the safety instructions
(see 17D, Gas injection, Introduction, Safety instructions for all operations).
NOTESAsk the customer if the problem always arises.
If it is not the case, do not replace the sensor, as it is not the cause.
Is the fault that the tank is not displaying full when it has just been filled with LPG?
Check that the tank has just been filled with LPG, otherwise refill it.
If the customer complaint is reproduced, continue fault finding.
If not, the fault does not always arise. Do not replace the sensor and deal
with the next customer complaint.
Disconnect the connector from the LPG tank sender and measure
the resistance between tracks A1 and A.
Replace the LPG tank sender if the resistance value is less than 5 kOhms,
because the sensor is incorrect.
If the fault is still present, contact the Techline.
Is the fault related to the LPG warning not being displayed when the tank is empty?
NOYES
YES
A
AFTER REPAIRCheck using the diagnostic tool.
Page 103 of 107

17C-103
MR-372-J84-17C000$944.mif
V2
GAS INJECTION
Fault finding - Fault finding chart (ALP)
LPG 3000
Program No: AB
Vdiag No: 08/10
17C
ALP 3 The engine stalls when switched to LPG mode
IMPORTANT
When carrying out an operation on an LPG supply circuit component, consult the safety instructions
(see 17D, Gas injection, Introduction, Safety instructions for all operations).
NOTESCheck that there is LPG in the tank.
Check the condition of the air filter.
Replace the filter if necessary.
Check that the LPG supply pipes are not pinched or crushed.
Replace the faulty pipes if necessary.
Check the expansion valve cooling circuit (see MR 364 Mechanics, 17D, LPG injection, Expansion valve).
Repair the circuit if necessary.
Measure the resistance between tracks 1 and 2 of the injectors.
Replace the injectors if their resistance value at approximately 20°C is not between:
0.77 Ω < R < 1.43 Ω
Check the following connections for insulation from earth, continuity and absence of extraneous
resistance:
Main relay track 5
Main relay track 5
Main relay track 5
Main relay track 5track 1of injector 1
track 1of injector 2
track 1of injector 3
track 1of injector 4
Check the insulation from + 12 V, the continuity and the absence of interference resistance of
the connections between:
LPG computer track G3
LPG computer track G4
LPG computer track H2
LPG Computer track H3track 2 of injector 1
track 2 of injector 2
track 2 of injector 3
track 2 of injector 4
If necessary, repair the defective connections.
AFTER REPAIRCheck using the diagnostic tool.
GAZ3000_V08_ALP3 / GAZ3000_V10_ALP3
Page 105 of 107

17C-105
MR-372-J84-17C000$944.mif
V2
GAS INJECTION
Fault finding - Fault finding chart (ALP)
LPG 3000
Program No: AB
Vdiag No: 08/10
17C
ALP 4 Idle speed faults
IMPORTANT
For any operation on a component of the LPG supply circuit, consult the safety instructions (see 17D,
LPG injection, Introduction, Safety instructions for all operations).
NOTESCheck that there is no fault in petrol mode.
Check that there is LPG in the tank.
Check that hoses are not blocked or pinched (especially after removal operations).
Repair the faulty component or components.
Check the condition of the air filter.
Replace the air filter if necessary.
Check the expansion valve cooling circuit (see MR 364 Mechanical, 17D, LPG injection, Expansion valve).
Repair the circuit if necessary.
Check the conformity of the spark plugs.
Replace the filter if necessary.
Test the operation of the injectors.
Run and interpret commands AC018 Cylinder 4 injector, AC019 Cylinder 3 injector, AC020 Cylinder 2
injector and AC021 Cylinder 1 injector.
AFTER REPAIRCheck using the diagnostic tool.
GAZ3000_V08_ALP4 / GAZ3000_V10_ALP4
Page 106 of 107

17C-106
MR-372-J84-17C000$944.mif
V2
GAS INJECTION
Fault finding - Fault finding chart (ALP)
LPG 3000
Program No: AB
Vdiag No: 08/10
17C
ALP 5 Faults occurring while driving
IMPORTANT
When carrying out an operation on an LPG supply circuit component, consult the safety instructions
(see 17D, Gas injection, Introduction, Safety instructions for all operations).
NOTESCheck that there is no fault in petrol mode.
Check that hoses are not blocked or pinched (especially after removal operations).
Repair the faulty component or components.
Check the condition of the air filter.
Replace the air filter if necessary.
Check the expansion valve cooling circuit (see MR 364 Mechanical, 17D, LPG injection, Expansion valve).
Repair the circuit if necessary.
Check the conformity of the spark plugs.
Replace the filter if necessary.
Test the operation of the injectors.
Run and interpret commands AC018 Cylinder 4 injector, AC019 Cylinder 3 injector, AC020 Cylinder 2
injector and AC021 Cylinder 1 injector.
AFTER REPAIRCheck using the diagnostic tool.
GAZ3000_V08_ALP5 / GAZ3000_V10_ALP5
Page 107 of 107
17C-107
MR-372-J84-17C000$944.mif
V2
GAS INJECTION
Fault finding - Fault finding chart (ALP)
LPG 3000
Program No: AB
Vdiag No: 08/10
17C
ALP 6 LPG leak
IMPORTANT
For any operation on a component of the LPG supply circuit, consult the safety instructions (see 17D,
LPG injection, Introduction, Safety instructions for all operations).
NOTESNone.
Open the plastic cover on the filler neck.
Check that the filler neck is in good condition.
Change the filler spigot if necessary.
Check that there are no leaks along the pipe that runs from the filler spigot to the LPG tank.
(Fill up with LPG to carry out this operation).
Repair the pipe if necessary.
AFTER REPAIRCheck using the diagnostic tool.
GAZ3000_V08_ALP6 / GAZ3000_V10_ALP6