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Connect the bornier in place of the computer and check the insulation, continuity and that there is no
interference resistance on the line:
Computer 54 2 Pinking sensor
Computer 44 1 Pinking sensor
Computer 2 Pinking sensor screening
Repair if necessary.
JSA052.0
INJECTION
Fault finding - Interpretation of XR25 bargraphs17
D7F 710
engine -
55 tracks
Erase the computer memory using G0**.
Try to start the engine. Switch the ignition on, then deal with the other faults.
Remember to carry out a status and parameter check.AFTER REPAIR
Bargraph 6 LH side illuminated Fiche n° 2 side 1/2
PINKING SENSOR CIRCUIT
XR25 aid:CO, CC- or CC+ line 54 or 44 of the computer
6
For certain faults BG 6LH will only illuminate permanently at 3000 rpm. for 1
minute. If BG 4LH or BG 5LH is also illuminated, check line 44 of the computer.
NOTES
The fault persists! Replace the injection computer.
IMPORTANT: The computer has probably been damaged by an electric shock. The cause of the damage
must be found before fitting a new computer.
The fault persists! Replace the pinking sensor.
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JSA052.0
INJECTION
Fault finding - Status and parameter checks
17
D7F 710
engine -
55 tracks
Engine stopped, ignition on.NOTES
Order of
operationsFunction to be
checkedAction Bargraph Display and notes Fault finding
6Throttle
position
potentiometer
.No load
# 17
Accelerator
pedal
slightly
depressed
Full load
# 1710 < X < 50
185 < X < 245
DIAG 2
7Pressure sensor
# 01X = Atmospheric
pressureDIAG 9
8Coolant
temperature
sensor# 02X = Engine temperature
± 5 °CDIAG 3
9Air
temperature
sensor# 03X = Temperature under
bonnet ± 5 °CDIAG 4
10 Fan assemblyG17*The fan must operateDIAG 17
11 Fault warning
lightSwitch
ignition onThe fault warning light
must illuminate then
extinguishDIAG 19
2
2
2
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JSA052.0
INJECTION
Fault finding - Status and parameter checks
17
D7F 710
engine -
55 tracks
Carry out the actions below if the engine does not start.
Otherwise, refer to the following pages.NOTES
Order of
operationsFunction to be
checkedAction Bargraph Display and notes Fault finding
1Flywheel signal
sensorStarterIlluminated if TDC
information detected
DIAG 5
2Fuel pump
G10*Fuel pump should be
heard to operateDIAG 6
3 IgnitionConnect
Optima
StationStarting test, complete
guide on Optima StationUse Optima
5800 Station
4Fuel pressureConnect
pressure
gauge to
fuel inlet
and activate
starter
motorThe pressure gauge must
show 2.5 bars Fuel pressure,
see Workshop
Repair
Manual or
section
5Injection
commandStarterFuel must come out of
the injector
DIAG 11
6Engine
compressionConnect
Optima
StationComplete guide on
Optima StationUse Optima
5800 Station
7 FlywheelConnect
Optima
StationOscilloscope.
Complete guide on
Optima StationUse Optima
5800 Station
3
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Page 225 of 363

Check the insulation and the continuity of the line:
Computer 19 C Throttle potentiometer
Computer 45 B Throttle potentiometer
Computer 46 A Throttle potentiometer
Repair if necessary.
JSA052.0
INJECTION
Fault finding - Status and parameter interpretation17
D7F 710
engine -
55 tracks
AFTER REPAIRStart the status and parameter check again from the beginning.
DIAG 2THROTTLE POTENTIOMETERFiche n° 27
XR25 aid:# 17 outside tolerances
# 17 does not vary when throttle moves
Status BG 2LH or 2RH, incorrect illumination
No fault bargraphs should be illuminated.
Ignition on or engine running.NOTES
Status bargraph 2RH
incorrect illuminationNoneNOTES
Check the resistance of the throttle potentiometer.
Replace the throttle potentiometer if necessary.
# 17 is fixedNoneNOTES
Check the resistance of the throttle potentiometer when the throttle is activated.
If the resistance varies, check the electrical lines of the sensor.
If the resistance does not vary, check that the sensor is connected mechanically to the throttle.
If necessary, replace the sensor.
# 17 outside tolerancesNoneNOTES
Check the upper and lower stops of the throttle.
Check the accelerator control (points of resistance and friction).
Repair.
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Check the insulation, continuity and that there is no interference resistance on the electrical line :
Computer 15 2 Coolant temperature sensor
Computer 44 1 Coolant temperature sensor
Repair.
JSA052.0
INJECTION
Fault finding - Status and parameter interpretation17
D7F 710
engine -
55 tracks
AFTER REPAIRStart the status and parameter check again from the beginning.
DIAG 3COOLANT TEMPERATURE
XR25 aid:# 02 = Engine temperature ± 5 °C
No fault bargraphs should be illuminated.
NOTES
If the value read is inconsistent, check the sensor correctly follows the standard table of values for
"resistance as a function of temperature".
Replace the sensor if the values are incorrect (
NOTE : If a sensor is incorrect, this is often due to an electric
shock).
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Check the insulation, continuity and that there is no interference resistance on the electrical line :
Computer 20 2 Air temperature sensor
Computer 46 1 Air temperature sensor
Repair.
JSA052.0
INJECTION
Fault finding - Status and parameter interpretation17
D7F 710
engine -
55 tracks
AFTER REPAIRStart the status and parameter check again from the beginning.
DIAG 4AIR TEMPERATUREFiche n° 27
XR25 aid:# 03 = Temperature under the bonnet ± 5 °C
No fault bargraphs should be illuminated.
NOTES
If the value read is incoherent, check the sensor correctly follows the standard table of values for
"resistance as a function of temperature".
Replace the sensor if the values are incorrect (
NOTE : If a sensor is incorrect, this is often due to an electric
shock).
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Check the insulation, continuity and that there is no interference resistance on the electrical line :
Computer 33 B Flywheel signal sensor
Computer 34 A Flywheel signal sensor
Repair.
JSA052.0
INJECTION
Fault finding - Status and parameter interpretation17
D7F 710
engine -
55 tracks
AFTER REPAIRStart the status and parameter check again from the beginning.
DIAG 5TDC DETECTIONFiche n° 27
XR25 aid:Status BG 3LH, incorrect illumination
No fault bargraphs should be illuminated.
When the starter motor is activated.NOTES
Check the resistance of the TDC sensor.
Replace the sensor if necessary.
Check the sensor is correctly mounted.
Repair if necessary.
Check the condition of the target (if it has been removed).
Repair if necessary.
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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.
JSA052.0
INJECTION
Fault finding - Status and parameter interpretation17
D7F 710
engine -
55 tracks
AFTER REPAIRStart the status and parameter check again from the beginning.
DIAG 6FUEL PUMPFiche n° 27
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.
17-186