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JSA052.0
INJECTION
Fault finding - Introduction
17
D7F 710
engine -
55 tracks
XR25 CHECKING STATUSES AND PARAMETERS
The status and parameter check is aimed at checking the statuses and parameters which do not illuminate
any fault bargraphs if they are outside of permitted tolerance values . This phase allows :
- Faults to be found without the illumination of fault bargraphs which may correspond to a customer
complaint (example : absence of no load information causing an unstable idle speed).
- The correct operation of the injection to be checked and the risk of faults appearing shortly after the
repair to be eliminated.
This section contains fault-finding for statuses and parameters, under their test conditions
(example : fault finding for # 01 ignition on and fault finding for # 01 engine running).
If a status does not operate normally or a parameter is outside of permitted tolerance values, consult the
fault-finding page indicated in the "Fault-finding" column.
XR25 CHECK CORRECT
If the XR25 check is correct, but the customer complaint persists, the problem must be dealt with through
customer complaints.
Treatment of customer complaints
This section has fault charts, which suggest a series of possible causes of the problem.
These lines of enquiry must only be used in the following cases :
- No fault bargraph appears on the XR25.
- No faults are detected during the checking of statuses and parameters.
- The vehicle is not operating correctly
POST-REPAIR CHECK
This operation is a simple check of the repair (by a command, or by an XR25 command mode ...).
This makes it possible to check that the system upon which the intervention has been carried out is correct
electrically.
It is an introduction to the road test.
ROAD TEST
A road test is essential in order to guarantee the correct operation of the vehicle and to test the quality of the
repair. Its role is to make sure that no faults occur (or will occur) when driving.
In order to be significant, the road test is subject to special driving conditions.
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JSA052.0
INJECTION
Fault finding - Introduction
17
D7F 710
engine -
55 tracks
Driving conditions for programming the adaptive variables:
During the road test, the engine speed must be stabilised for a few moments between:
260 < # 01 < 385 mbars
then 385 < # 01 < 510 mbars
then 510 < # 01 < 635 mbars
then is 635 < # 01 < 760 mbars
then 760 < # 01 < 970 mbars
Do not exceed an engine speed of 4400 rpm
The engine must be warm (coolant temperature > 75 °C).
For this test, start from a fairly low engine speed, in 3rd or 4th gear, and apply progressive acceleration to
stabilise at the pressure required for 10 seconds in each zone.
The test must then be continued by driving normally, in a varied manner for 3 to 6 miles (5 to 10 km).
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Connect the bornier in place of the computer and check the insulation and continuity of the line:
Computer 18 Earth
Computer 2 Earth
Computer 3 Earth
Computer 11 7 Diagnostic socket
Computer 38 15 Diagnostic socket
Computer 1 5 Main relay
Computer 40 2 Main relay
Computer 48 2 Fuel pump relay
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 1 RH extinguishedFiche n° 27 side 1/2
XR25 CIRCUIT
XR25 aid:No connection, CO, CC-, CC+
1
This bargraph must be illuminated for fault findingNOTES
Test the XR25 on another vehicle.
Check:
- the injection, engine and passenger compartment fuses,
- the connection between the XR25 and the diagnostic socket,
- the position of the ISO selector (S8),
- the conformity of the cassette.
Repair if necessary.
Check:
- the presence of + 12 V on track 16 and earth on track 5 of the diagnostic socket,
- that the XR25 cable is in good condition.
Repair if necessary.
Check, ignition on, for 12 V on track:
- 1 on the main relay,
- 3 on the main relay,
- 1 on the fuel pump relay.
Repair if necessary.
Ignition on, check for 12 V on track 5 of the main relay:
- If there is 12 V on track 5 of the main relay: replace the fuel pump relay.
- If there is not 12 V on track 5 of the main relay: replace the main relay.
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Connect the bornier in place of the computer and check the insulation and continuity of the line:
Computer 17 C Oxygen sensor
Repair if necessary.
JSA052.0
INJECTION
Fault finding - Interpretation of XR25 bargraphs17
D7F 710
engine -
55 tracks
Turn the engine, switch the ignition on and 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 3 RH side illuminated or flashing Fiche n° 27 side 1/2
OXYGEN SENSOR CIRCUIT
XR25 aid:CO, CC- or CC+line 17 of the computer
CO line 18 of the computer
3
If BG 3RH is flashing, increase the engine speed to 2500rpm for 5 minutes.
If BG 3RH becomes permanently illuminated, deal with the fault.
NOTES
Check the connection and the condition of the connector on the oxygen sensor.
Check, ignition on during the timed phase, for :
- earth on track B of the oxygen sensor,
- + 12 V after the fuel pump relay on track A of the oxygen sensor.
Repair if necessary.
Check for the presence of earth on track 18 of the injection computer.
Repair if necessary.
The fault persists. Replace the oxygen sensor.
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.
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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 33 B Target sensor
Computer 34 A Target sensor
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 5 RH side illuminated or flashingFiche n° 2 side 1/2
FLYWHEEL SIGNAL CIRCUIT
XR25 aid:*25 = CO.0 =>CO or CC- line 33 or 34 of the computer
*25 = CC.0 =
>CC- line 33 or 34 of the computer
*25 = In =
>sensor incorrectly connected
5
Try to illuminate BG 5RH when the starter is activated.
BG 5RH is often seen to flash if *25 = dEF as its permanent illumination is very
quick. In certain cases, BG 5RH may illuminate then extinguish.
NOTES
Check the resistance of the target sensor.
Replace the sensor if necessary.*25 = CO.0
*25 = CC.0
Check the condition of the flywheel, especially if it has been removed.
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.
Check the target sensor has been correctly connected (the sensor connector must
not be inverted).
Repair if necessary.*25 = In
The fault persists! Replace the sensor.
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Connect the bornier in place of the computer and check the insulation and continuity of the line.
Computer 43 6 Instrument panel
Repair.
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 12 LH side illuminatedFiche n° 27 side 1/2
FAULT WARNING LIGHT CIRCUIT
XR25 aid:CO, CC- or CC+ line 43 of the computer
12
NoneNOTES
Check the condition of the warning light and its feed.
Repair if necessary.
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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 15 LH side illuminated Fiche n° 27 side 1/
COMPUTER AC CONNECTION CIRCUIT
XR25 aid:CC + 12 V line 51 of the computer
15
Connect the bornier in place of the computer and check the insulation and continuity of line 51 of the
computer.
Repair if necessary.
Check that the vehicle has air conditioning, if not, ignore this bargraph.NOTES
If the fault persists, consult the air conditioning fault finding section.
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JSA052.0
INJECTION
Fault finding - Status and parameter checks
17
D7F 710
engine -
55 tracks
Order of
operationsFunction to be
checkedAction Bargraph Display and notes Fault finding
8Air
conditioningAC selected
# 06
# 44
# 06
# 44Extinguished if fast idle is
not active
Illuminated if the air
conditioning requests
compressor operation
Illuminated if the
injection authorises
compressor operation
690 ≤ X ≤ 790 rpm
300 ≤ X ≤ 4000 W
800 ≤ X ≤ 900 rpm
300 ≤ X ≤ 4000 W
DIAG 16
9Power assisted
steering
prestostatTurn wheels
to full lockIlluminated when wheels
turned to full lockDIAG 18
Carry out the actions below (engine warm, at idle speed, no consumers)
if the engine starts.
Otherwise refer to the previous pages.
NOTES
10
10
9
13
10
9
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