fuel pump RENAULT SCENIC 2008 J84 / 2.G Gas Injection LPG 3000 Workshop Manual

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-10
MR-372-J84-17C000$118.mif
V2
GAS INJECTION
Fault finding - System operation
LPG 3000
Program No: AB
Vdiag No: 08/10
17C
The GAS 3000 computer manages "gas" actuator control, i.e. the "gas" injectors, the gas system relays and solenoid
valves, the fuel pump cut-off relay and the management of the fuel sender. Before switching to "Gas" mode, the
computer always checks that the pressure and the temperature of the gas are correct and that the "gas" solenoid
valves are open.
The combustible material is stored in an independent toric tank. LPG is stored in a semi-gaseous state at a pressure
of approximately 15 bar.
CNG is stored in a cylindrical tank in a gaseous state at a pressure of approximately 200 bar, and is transported to
the expansion valve/reducer via a rigid high pressure pipe. The rest of the system is a low pressure pipe going from
the expansion valve/reducer to the injectors. For CNG, there is a gas filter between the expansion valve and the rail.
Malfunctions / Special cases
These are characterised by operation in Petrol mode, although the driver has selected LPG mode.
An operational fault must be caused by the LPG system if it cannot be reproduced in Petrol mode.
Forced Petrol mode when LPG is faulty.
The level 1 warning light is controlled by the petrol injection computer; the gas warning light is controlled by the GAS
3000 computer.
The system automatically switches to "petrol" mode when the tank is empty or when the conditions allowing
operation in "gas" mode are not satisfied.

17C-15
MR-372-J84-17C000$295.mif
V2
17C
GAS INJECTION
Fault finding - Fault summary table
Tool fault Associated DTC Description
DF0032617 Engine speed inconsistency
DF0071B47 Main relay circuit
DF0131B40 Tank solenoid valve circuit
DF0141B42 Gauge supply circuit
DF0161685 Impact detected
DF0171094 LPG leak detection downstream of expansion valve
DF0180512 + after ignition feed
DF0191B05 LPG pressure sensor circuit
DF0201B45 Fuel sender switching relay circuit
DF0211B46 LPG tank solenoid valve relay circuit
DF0221B60 Computer
DF0241B43 Fuel pump cut-off relay circuit
DF026C073 Multiplex network
DF0291B20 LPG tank sender signal voltage
DF0300657 LPG tank sender supply voltage
DF0311B61 LPG pressure downstream from expansion valve
DF061C100 Multiplex network
DF0740336 TDC signal circuit
DF0800560 Battery voltage
DF0811B32 Cylinder 2 injector circuit
DF0831B00 LPG pressure sensor circuit
DF0871B34 Cylinder 4 injector circuit
DF0881B33 Cylinder 3 injector circuit
DF0921B05 Expansion valve downstream LPG pressure sensor circuit
DF0951B10 LPG temperature sensor circuit
DF0960641 Sensor supply voltage
DF0981B31 Cylinder 1 injector circuit
DF0991B49 Instrument panel indicator circuit
DF1031B41 LPG expansion valve solenoid valve circuit
LPG 3000
Program No: AB
Vdiag No: 08/10
MR-372-J84-17C000$295.mif

17C-19
MR-372-J84-17C000$354.mif
V2
GAS INJECTION
Fault finding - Interpretation of faults
LPG 3000
Program No: AB
Vdiag No: 08/10
17C
DF013
CONTINUED
Check for earth on track E (for Mégane 2) or on track B (for Logan) of the LPG tank solenoid valve.
Repair if necessary.
With the engine running, check that the LPG tank solenoid valve relay clicks when LPG mode is selected.
If the fault is still present, check the insulation in relation to +12 V and the continuity and absence
of interference resistance on the following connections:
LPG computer track E4 track 2 of the LPG tank solenoid valve relay
Repair if necessary.
With the ignition on, check for + 12 volts on track C2 of the LPG computer.
Check the insulation in relation to + 12V and the continuity and absence of interference resistance on
the connection between:
LPG computer track C2 track 1 of the LPG tank solenoid valve relay
Repair if necessary.
With the ignition on, check that the relay and the fuel pump are supplied with + 12V.
Check the insulation in relation to + 12V and the continuity and absence of interference resistance on
the connection between:
For Mégane 2:
Fuel pump relay track 2
For Logan:
Fuel pump relay track B5track 3 of the LPG tank solenoid valve relay
track 3 of the LPG tank solenoid valve relay
Repair if necessary.
If the fault is still present, deal with the other faults, then proceed to the conformity check.
AFTER REPAIRDeal with any faults displayed by the diagnostic tool.
Clear the computer memory.
Carry out a road test followed by another check with the diagnostic tool.

17C-21
MR-372-J84-17C000$354.mif
V2
GAS INJECTION
Fault finding - Interpretation of faults
LPG 3000
Program No: AB
Vdiag No: 08/10
17C
DF016
PRESENT
IMPACT DETECTED
1.DEF: Impact detected
2.DEF: Non-compliance with emission control standards
NOTESPriority when dealing with a number of faults:
If faults DF021 LPG tank solenoid valve relay circuit or fault DF018 + After ignition
feed supply are present or stored, deal with these faults first.
Special note:
As soon as the LPG computer receives this signal, engine operation is prohibited.
If the vehicle has been involved in an accident:
Carry out any necessary repairs,
–clear the fault,
–switch off the ignition,
–wait for the engine immobiliser indicator light to flash,
–switch on the ignition,
If the fault does not recur, end the fault finding procedure.
If the fault recurs, carry out fault finding on the AIRBAG computer.
If the vehicle has not been involved in an accident:
Check for + 12V on track 3 of the fuel pump cut-off relay and the LPG tank relay.
Repair if necessary.
AFTER REPAIRDeal with any faults displayed by the diagnostic tool.
Clear the computer memory.
Carry out a road test followed by another check with the diagnostic tool.
GAZ3000_V08_DF016P / GAZ3000_V10_DF016

17C-26
MR-372-J84-17C000$354.mif
V2
GAS INJECTION
Fault finding - Interpretation of faults
LPG 3000
Program No: AB
Vdiag No: 08/10
17C
DF021
PRESENT
OR
STOREDLPG TANK SOLENOID VALVE RELAY CIRCUIT
CC.1: Short circuit to + 12 Volts
CO.0: Open circuit or short circuit to earth
1.DEF: Non-compliance with emission control standards
NOTESPriority when dealing with a number of faults:
If fault DF024 Fuel pump cut-off relay circuit is present or stored, deal with this fault
first.
Conditions for applying the fault finding procedure to stored faults:
The fault is declared present after the engine has been started and switched to LPG
mode.
Manipulate the wiring harness between the LPG computer and the LPG tank solenoid valve relay in order to
produce a change in status (present ↔ stored).
Look for possible damage to the wiring harness and check the condition and connection of the LPG tank
solenoid valve relay and its connections.
If necessary, repair or replace the connector.
With the ignition on, check for + 12V on track 1 of the LPG tank solenoid valve relay and track C2 of the LPG
computer.
If no + 12 V:
–disconnect the battery,
–in the Protection and Switching Unit, disconnect the grey connector,
–check the cleanliness and condition of the connections,
–Use the universal bornier to check the continuity of the following connection:
For Mégane 2:
Protection and Switching Unit, grey connector, track 1
For Logan:
Fuse box, track S4track 3 of the main relay
track A5 of the main relay
Repair if necessary.
Check for + 12V on track 3 of the LPG tank solenoid valve relay.
If + 12V is not present, use the universal bornier to check the continuity of the following connection:
For Mégane 2:
Tank solenoid valve relay track 3
For Logan:
Double control relay unit track B3track 5 of the fuel pump relay
track B5 of the fuel pump relay
Repair if necessary.
AFTER REPAIRDeal with any faults displayed by the diagnostic tool.
Clear the computer memory.
Carry out a road test followed by another check with the diagnostic tool.
GAZ3000_V08_DF021 / GAZ3000_V10_DF021

17C-29
MR-372-J84-17C000$354.mif
V2
GAS INJECTION
Fault finding - Interpretation of faults
LPG 3000
Program No: AB
Vdiag No: 08/10
17C
DF024
PRESENT
OR
STOREDFUEL PUMP CUT-OFF RELAY CIRCUIT
CO.0: Open circuit or short circuit to earth
CC.1: Short circuit to + 12 Volts
1.DEF: Non-compliance with emission control standards
NOTESPriority when dealing with a number of faults:
If fault DF021 LPG tank solenoid valve relay circuit is present or stored, deal with
this fault first.
Conditions for applying the fault finding procedure to stored faults:
The fault is declared present after the engine has been running for 10 seconds in
LPG mode.
Manipulate the wiring harness between the LPG computer and the fuel pump cut-off relay in order to produce
a change in status (present ↔ stored).
Look for any damage to the wiring harness and check the connection and condition of the fuel pump cut-off
relay and its connections.
Check the insulation in relation to earth and the continuity and the absence of interference resistance on
the connection between:
For Mégane 2:
Main relay track 5
For Logan:
Double control relay unit track A3track 1 of the fuel pump cut-off relay
track B5 of the fuel pump cut-off relay
Repair if necessary.
Check the insulation in relation to + 12V and the continuity and absence of interference resistance on
the connection between:
LPG computer track F3 track 2 of the fuel pump cut-off relay
Repair if necessary.
In LPG operating mode, using status ET025 Fuel pump, check that status ET025 is ACTIVE when starting
and then changes to INACTIVE after 1 minute.
If ET025 does not change to INACTIVE, check for earth on track 2 of the fuel pump cut-off relay.
If, with the ignition on, the computer does not control the fuel pump cut-off relay on track 2 through an earth,
contact your Techline.
If the fault is still present, replace the fuel pump cut-off relay.
If the fault is still present, deal with the other faults, then proceed to the conformity check.
AFTER REPAIRDeal with any faults displayed by the diagnostic tool.
Clear the computer memory.
Carry out a road test followed by another check with the diagnostic tool.
GAZ3000_V08_DF024 / GAZ3000_V10_DF024

17C-62
MR-372-J84-17C000$472.mif
V2
LPG 3000
Program No.
Vdiag No: 08/10GAS INJECTION
Fault finding - Conformity check17C
SUB-FUNCTION: OPERATION IN LPG MODE (CONTINUED 2)
NOTESOnly perform this conformity check after a complete check with the diagnostic tool.
The values indicated in this conformity check are given as examples.
Application condition: Engine stopped, ignition on and LPG mode selected.
Order FunctionParameter or Status
checked or ActionDisplay and notes Fault finding
8LPG flow rate
settingPR111:LPG flow rate
settingIndicates the LPG flow rate
setpoint in g/h.
PR111 = 0 g/h
NONE
9LPG injection
durationPR110:LPG injection
timingDisplays the injection duration
in ms.
PR110 = 0 ms
10
Tank senderPR013:LPG tank
sender supply
voltage4.8 V < PR008< 5.2 VIn the event of a fault,
apply the interpretation of
fault DF030 LPG tank
sender supply voltage.
11 PR009:LPG tank
sender signal
voltageIndicates the signal voltage
compared to the pressure in the
LPG tank.For Logan: In the event
of a fault, apply the
interpretation of fault
DF029 LPG tank sender
signal voltage.
For Mégane II: In the
event of a fault, apply the
interpretation of fault
DF029 LPG tank sender
signal voltage
and parameters
PR009 and PR116. 12 PR116:Sender
resistanceFor Logan: Ignore this
parameter.
For Mégane II:
Tank full:
20 Ω ± 2 Ω
Reserve tank:
290 Ω ± 2 Ω
Tank empty:
320 Ω ± 2 Ω
13LPG
temperaturePR113:LPG
TemperatureGives the LPG temperature
in °C.
- 40°C < PR113 < 120°CNONE
14 Fuel pump ET025:Fuel pumpACTIVEACTIVE when operating in
Petrol mode. If there is
inconsistency, carry out
a full fault finding
procedure on the petrol
injection system.
Deal with any other faults.

17C-64
MR-372-J84-17C000$472.mif
V2
LPG 3000
Program No.
Vdiag No: 08/10GAS INJECTION
Fault finding - Conformity check17C
SUB-FUNCTION: OPERATION IN PETROL MODE (CONTINUED)
NOTESOnly perform this conformity check after a complete check with the diagnostic tool.
The values indicated in this conformity check are given as examples.
Application conditions: Engine switched off, ignition on and Petrol mode
selected.
Order FunctionParameter or Status
checked or ActionDisplay and notes Fault finding
7Fuel pump ET025:Fuel pumpACTIVEACTIVE when operating in
Petrol mode. If there is
inconsistency, carry out
a full fault finding procedure
on the petrol injection
system. Deal with any other
faults.
8
Petrol
injection
signalPR002:Coolant
temperatureIndicates the temperature
– of water in °C.
– of air in °C.
Check the consistency
of the temperatures by
performing fault finding on
the petrol computer.
With a cold engine, the two
temperatures should be
almost identical.In the event of a fault, carry
out a full fault finding
procedure on the petrol
injection system. Deal with
any other faults. 9PR103:Air temperature

17C-73
MR-372-J84-17C000$472.mif
V2
LPG 3000
Program No.
Vdiag No: 08/10GAS INJECTION
Fault finding - Conformity check17C
SUB-FUNCTION: OPERATION IN LPG MODE (CONTINUED 2)
NOTESOnly perform this conformity check after a complete check with the diagnostic tool.
The values indicated in this conformity check are given as examples.
Application conditions: Engine running at idle speed at 80°C and LPG mode
selected.
13LPG
temperaturePR113:LPG
TemperatureGives the LPG temperature
in °C.
- 40°C < PR113 < 120°CIn the event of a fault, carry
out a full fault finding
procedure on the petrol
injection system.
Deal with any other faults.
14 Fuel pump ET025:Fuel pumpINACTIVE after 1 minuteACTIVE when operating in
Petrol mode. If there is
inconsistency, carry out
a full fault finding procedure
on the petrol injection
system.
Deal with any other faults.