air filter RENAULT SCENIC 2008 J84 / 2.G Gas Injection LPG 3000 Workshop Manual

17C-8
MR-372-J84-17C000$059.mif
V2
GAS INJECTION
Fault finding - Introduction
LPG 3000
Program No: AB
Vdiag No: 08/10
17C
ROAD TEST (in Petrol mode, then in LPG mode)
–check that the stabilisation time is normal,
–check that the engine does not stall under sudden braking and that it maintains a stable idle speed until the vehicle
comes to a stop,
–put the vehicle in 4th gear, at a steady speed of 36 mph (60 km/h). Check that the vehicle accelerates
progressively under full load acceleration.
Maintenance operations:
–no adjustment,
–removal of internal components is not permitted,
–if LPG clips are removed, they must be replaced,
–if LPG unions are removed, they must be replaced.
The tank must be bled before removing:
●the fuel tank,
●a component bolted to the fuel tank,
To remove the following, bleed all gas contained in the gas circuit (except the gas in the tank):
●the filler neck,
●the pipes,
●the filter,
●the pressure relief valve,
●the solenoid valve. IMPORTANT
Before performing any work on the vehicle, drain the LPG circuit.
Only personnel who have undergone special LPG training can work with gas unions where gas is circulating and
which run from the expansion valve via the fuel tank.
Equally, only these persons are permitted to perform servicing and repair operations on LPG vehicles.
Workshops can only carry out work on the fuel tank if they have a degassing burner. If the tank cannot be
degassed, do not carry out any work and contact the Comité Français du Butane et du Propane (French
Butane and Propane Commission) by fax on 01 41 97 02 89.

17C-9
MR-372-J84-17C000$118.mif
V2
17C
GAS INJECTION
Fault finding - System operation
1. System operation:
Composition
–The LPG injection system consists of the:
–LPG tank,
–fuel sender,
–overpressure unit (thermally triggered),
–LPG solenoid valve relay,
–tank solenoid valve,
–reducer (LPG) or expansion valve (CNG),
–expansion valve,
–filling spigot or socket,
–LPG hose,
–tank pressure sensor,
–LPG pipes,
–unions,
–airtight cover,
–regulator valve or anti-return valve,
–excess pressure valve,
–LPG filter,
–temperature and pressure sensor,
–LPG computer,
–LPG expansion solenoid valve,
–gas injectors,
–LPG or petrol selection switch,
–fuel sender relay,
–LPG tank relay,
–fuel pump cut-off relay.
Operating principle
The GAS 3000 computer electronically manages the operation of the LPG systems (Liquefied Petroleum Gas) and
CNG (Compressed Natural Gas).
The engine must be started in Petrol mode. The vehicle will automatically switch to "Gas" mode after starting if the
"gas" configuration was selected beforehand. "Petrol" mode switches to "gas" mode after a certain time delay, which
depends on the engine coolant temperature.
Petrol mode operates autonomously. Information is shared between the Petrol computer and the LPG computer via
a CAN connection.
The K line shared by the two computers allows diagnostics to be run on both the petrol and the LPG systems.
The Petrol computer is also the supervisor of the LPG system and includes, in addition to petrol-specific functions,
functions for adapting engine management programming to LPG operation.
Therefore, the Petrol computer includes settings and variables that are specific for LPG operation, e.g. ignition
advance adjustment in LPG mode, LPG flow rate setting, richness regulation, engine operating mode, etc.
It controls the choice of program (petrol start-up etc.) and controls the transition phases for switching from one
operating mode to the other: Petrol → Gas or Gas → Petrol. The fuel pump is regularly supplied to keep the system
under pressure in the event of a possible return to "Petrol" mode (if the "Gas" tank is detected as empty or if a fault
is detected).
LPG 3000
Program No: AB
Vdiag No: 08/10
MR-372-J84-17C000$118.mif

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

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

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