Page 159 of 363
Check the insulation and continuity of the wiring:
Fuel pump relay 5 Impact sensor
Impact sensor C1 Fuel pump
Repair if necessary.
Check the 25A fuel pump fuse.
Check the insulation and continuity of the wiring:
Fuel pump fuse 3 Fuel pump relay
Repair if necessary.
JSA051.0
INJECTION
Fault finding - Status and parameter interpretation17
D7F 710
engine -
35 tracks
AFTER REPAIRStart the status and parameter check again from the beginning.
DIAG 6
Fiche n° 27
FUEL PUMP
XR25 aid:The command mode should cause the fuel pump to operate
No fault bargraphs should be illuminated.NOTES
Check the hygiene and presence of earth on track C2 of the fuel pump.
If + 12 V is not reaching the fuel pump, replace the fuel pump relay.
If + 12 V is reaching the fuel pump, replace the fuel pump.
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Page 160 of 363

Check the insulation and continuity of the line:
Computer 11 D Idle speed regulation motor
Computer 12 A Idle speed regulation motor
Computer 28 B Idle speed regulation motor
Computer 29 C Idle speed regulation motor
Repair if necessary and continue fault finding using the value for # 06.
JSA051.0
INJECTION
Fault finding - Status and parameter interpretation17
D7F 710
engine -
35 tracks
AFTER REPAIRStart the status and parameter check again from the beginning.
DIAG 7
IDLE SPEED REGULATIONFiche n° 27
XR25 aid:Engine speed , Minimum < # 06 < Maximum
No fault bargraphs should be illuminated.NOTES
Check the resistance of the idle speed regulation stepping motor.
Replace the idle speed regulation valve if necessary.
# 06 < MinimumThe idle speed is too lowNOTES
Idle speed regulation is not maintaining the idle speed.
- Clean the air supply circuit (throttle body, idle regulation valve), since it is probably contaminated.
- Check the engine oil level (too high ---
> splashing).
- Check and ensure correct fuel pressure.
- Using the OPTIMA 5800 station, check the engine compression.
- Check the valve clearances and the timing.
If all these points are correct, replace the idle regulation motor.
# 06 > MaximumThe idle speed is too highNOTES
An air leak may be affecting the idle speed regulation programming.
- Check the connections on the manifold.
- Check the hygiene of the pipes on the manifold.
- Check the pneumatically controlled solenoid valves.
- Check the manifold gaskets.
- Check the throttle body gaskets.
- Check the sealing of the brake servo.
- Check the restrictions are present in the oil vapour rebreathing circuit.
- Check the fuel pressure.
If all these points are correct, replace the idle speed regulation motor.
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Page 161 of 363
The pinking sensor should give a signal which is variable and not zero, to prove that it is recording the
mechanical vibrations of the engine.
If the signal is zero:
- Check the sensor is correctly screwed in.
- Check the insulation and continuity of the wiring:
Computer 1 2 Pinking sensor
Computer 15 1 Pinking sensor
Computer 16 Pinking sensor screening
If necessary, replace the sensor.
JSA051.0
INJECTION
Fault finding - Status and parameter interpretation17
D7F 710
engine -
35 tracks
AFTER REPAIRStart the status and parameter check again from the beginning.
DIAG 8
Fiche n° 27
ANTI-PINKING CIRCUIT
XR25 aid:# 13 is not zero and variable for fast idle or under load
No fault bargraphs should be illuminated.NOTES
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Page 162 of 363

Check the insulation, continuity and that there is no interference resistance
on the line:
Computer 5 C Pressure sensor
Computer 15 A Pressure sensor
Computer 23 B Pressure sensor
Repair if necessary.
JSA052.0
INJECTION
Fault finding - Status and parameter interpretation17
D7F 710
engine -
35 tracks
AFTER REPAIRStart the status and parameter check again from the beginning.
DIAG 9
Fiche n° 27
PRESSURE CIRCUIT
XR25 aid:Ignition on # 01 not coherent
At idle speed # 01 < Minimum or # 01 > Maximum
# 16 not coherent
No fault bargraphs should be illuminated.NOTES
# 01 not coherent
ignition on
# 01 < Minimum at idle
speed
# 16 not coherent
If all these points are correct, replace the sensor.
A vacuum pump with a pressure gauge may be used to check coherence with
# 01 and to show a faulty sensor.
# 01 > Maximum at idle
speedThe manifold pressure is often a sign of incorrect engine operation. Check
- the sealing of the pipe between the manifold and the sensor,
- the valve clearances,
- the canister bleed valve which should be closed at idle speed,
- cylinder compression using the OPTIMA 5800 station.
If all these points are correct, replace the sensor.
A vacuum pump with a pressure gauge may be used to check coherence with
# 01 and to show a faulty sensor.
17-117
Page 163 of 363
JSA051.0
INJECTION
Fault finding - Status and parameter interpretation17
D7F 710
engine -
35 tracks
AFTER REPAIRStart the status and parameter check again from the beginning.
DIAG 10
Fiche n° 27
RICHNESS REGULATION
XR25 aid:Richness regulation faulty
No fault bargraphs should be illuminated.
Ignition correct (a check may be made using the OPTIMA 5800 station).
No other status bargraph should show a fault.
NOTES
Check the sealing of the canister bleed valve (a leak can disrupt the richness considerably).
Check the sealing of the exhaust pipe upstream from the oxygen sensor.
Check the sealing of the inlet manifold.
If the vehicle has only been driven in town, the sensor is contaminated (try driving under load).
Check the fuel pressure.
If the idle speed is unstable, check the valve clearances.
Check the injectors (flow and shape of the jet).
If necessary, replace the oxygen sensor.
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Page 164 of 363
Check the insulation and continuity of the line:
injectors 1 and 4 Computer 33 2 injectors
injectors 2 and 3 Computer 32 2 injectors
Repair if necessary.
JSA051.0
INJECTION
Fault finding - Status and parameter interpretation17
D7F 710
engine -
35 tracks
AFTER REPAIRStart the status and parameter check again from the beginning.
DIAG 11
Fiche n° 27
INJECTOR
XR25 aid:CO or CC - line 33 of the computer for injectors 1 and 4
CO or CC - line 32 of the computer for injectors 2 and 3
No fault bargraphs should be illuminated.NOTES
Check the resistance of the faulty injector.
Replace it if necessary.
During command mode operation, check for + 12 Volts on track 1 of the faulty injector.
Repair.
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Page 165 of 363
JSA051.0
INJECTION
Fault finding - Status and parameter interpretation17
D7F 710
engine -
35 tracks
AFTER REPAIRStart the status and parameter check again from the beginning.
DIAG 12
IMMOBILISERFiche n° 27
XR25 aid:Status BG 3RH, incorrect illumination
No fault bargraphs should be illuminated.NOTES
Check the insulation and continuity of the wiring for track 30 on the injection computer.
If the fault persists, refer to the immobiliser fault finding.
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Page 166 of 363
if the value read is incoherent:
- Check that the sensor is correctly mounted and supplied:
•+12 V on A1
• Earth on B2
- Check the insulation, continuity and that there is no interference resistance on the line:
Computer 8 B1 vehicle speed sensor
Repair.
JSA051.0
INJECTION
Fault finding - Status and parameter interpretation17
D7F 710
engine -
35 tracks
AFTER REPAIRStart the status and parameter check again from the beginning.
DIAG 13
Fiche n° 27
VEHICLE SPEED
XR25 aid:# 18 = Speed read on speedometer in km/h
No fault bargraphs should be illuminated.
Check on a road test.NOTES
The fault persists! Replace the speed sensor.
17-121