Page 66 of 363

Connect the bornier in place of the computer and check the insulation, continuity and that there is no
interference resistance on the line:
Computer 8 2 Pinking sensor
Computer 44 1 Pinking sensor
Computer 31 Pinking sensor screening
Repair if necessary.
JF 5111.0
INJECTION
Fault finding - Interpretation of XR25 bargraphs17
E7J 780
engine
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 or flashingFiche n° 27 side 1/2
PINKING SENSOR CIRCUIT
XR25 aid:CO, CC- or CC+ line 8 or 44
6
If BG 6LH is flashing, erase the computer memory using G0**. Run the engine at
3000 rpm for 3 min. If BG 6LH becomes permanently illuminated or flashes, deal
with this fault. If BG 4LH or BG 5LH is also illuminated, check line 44 on 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 in question.
17-18
Page 79 of 363
JF5111.0
INJECTION
Fault finding - Status and parameter checks
17
E7J 780
engine
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
# 1716 < X < 50
185 < X < 243
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*Fan must operateDIAG 17
11Fault warning
lightSwitch
ignition onFault warning light must
illuminate then
extinguishDIAG 19
2
2
2
17-31
Page 80 of 363
JF5111.0
INJECTION
Fault finding - Status and parameter checks
17
E7J 780
engine
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
sensor StarterIlluminated if TDC
information is 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
motorPressure gauge must
show
2.5 bars Fuel pressure,
see Workshop
Repair
Manual or
section
5Injector
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
17-32
Page 85 of 363

Check the insulation and continuity of the line:
Computer 19 2 Throttle potentiometer
Computer 45 1 Throttle potentiometer
Computer 46 3 Throttle potentiometer
Repair if necessary.
JF5111.0
INJECTION
Fault finding - Status and parameter interpretation17
E7J 780
engine
AFTER REPAIRStart the status and parameter check again from the beginning.
DIAG 2
THROTTLE 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
If the fault is still present, replace the throttle potentiometer.
# 17 is fixedNoneNOTES
Check the resistance of the throttle potentiometer when the throttle butterfly is moved.
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 butterfly.
Check the accelerator control (points of resistance and friction).
Repair.
17-37
Page 86 of 363
Check the insulation, continuity and that there is no interference resistance on the electrical line :
Computer 15 B2 Coolant temperature sensor
Computer 44 B1 Coolant temperature sensor
Repair.
JF5111.0
INJECTION
Fault finding - Status and parameter interpretation17
E7J 780
engine
AFTER REPAIRStart the status and parameter check again from the beginning.
DIAG 3
Fiche n° 27
COOLANT TEMPERATURE
XR25 aid: # 02 = Engine temperature ± 5 °C
No fault bargraphs should be illuminated.NOTES
If the value read is incoherent, check the sensor is correctly following 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).
17-38
Page 87 of 363
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.
JF5111.0
INJECTION
Fault finding - Status and parameter interpretation17
E7J 780
engine
AFTER REPAIRStart the status and parameter check again from the beginning.
DIAG 4
Fiche n° 27
AIR TEMPERATURE
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 is correctly following 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).
17-39
Page 88 of 363
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. If necessary, replace the sensor.
JF5111.0
INJECTION
Fault finding - Status and parameter interpretation17
E7J 780
engine
AFTER REPAIRStart the status and parameter check again from the beginning.
DIAG 5
Fiche n° 27
TDC DETECTION
XR25 aid:Status BG 3LH, incorrect illumination
No fault bargraphs should be illuminated.
When the starter motor is activated.NOTES
Check the sensor is correctly mounted.
Check the condition of the target (if it has been removed).
17-40
Page 89 of 363
Check the insulation and continuity of the wiring:
Fuel pump relay L5 Impact sensor
Impact sensor C1 Fuel pump
Repair if necessary.
Check the 30A fuel pump fuse.
Check the insulation and continuity of the wiring:
Fuel pump fuse L3 Fuel pump relay
Repair if necessary.
JF5111.0
INJECTION
Fault finding - Status and parameter interpretation17
E7J 780
engine
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.
Check the impact sensor is correctly clipped in.
17-41