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DPCF01 1.0
LUCAS DIESEL INJECTION
Fault finding - Checking conformity
13
Engine warm at idle speed after at least one operation of the engine cooling fan
assembly (air conditioning not selected).NOTES
Order of
operationsFunction to check Action Bargraph Display and notes
5 EGR solenoid valve After starting
phase for
40 seconds
#24
After
40 seconds
#24EGR solenoid valve fed
X = 82
X = 0
6Computer
configuration
With AC
Without ACG50*3*
G50*8*
G50*4*
G50*9*With AC
With PAS with pump
Without AC
With conventional PAS
3
3
18
18
19
19
13-36
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JF5111.0
INJECTION
Fault finding- Introduction
17
E7J 780
engine
SETTING UP DIALOGUE BETWEEN THE XR25 AND THE COMPUTER
- Connect the test kit to the diagnostic socket.
- Put the selector on S8
- Switch on the ignition.
- Enter D13 9.NJ
COMPUTER IDENTIFICATION
The computer is not identified by reading a fault code but by reading the Part Number directly from the
computer. After having set up a dialogue with the computer:
ENTER G70*7700
XXX
XXX
The Part Number will then appear on the central display in three sequences.
Each sequence is displayed for approximately two seconds. The display is repeated twice .
ERASING THE MEMORY (ignition on)
After an operation on the injection system the computer’s memory can be erased by using the code G0** .
17-1
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JF5111.0
INJECTION
Fault finding - Introduction
17
E7J 780
engine
DESCRIPTION OF THE FAULT-FINDING PHASES
The process described below is to be carried out in all cases of faults.
XR25 FAULT-CHECKING
This phase is the essential starting point for any intervention on the vehicle.
There are several constraints to the treatment of the bargraphs :
- A priority in the order of treatment when several bargraphs are illuminated.
- The interpretation of a bargraph depending on whether it is constantly illuminated or flashing .
1 - Order of priority
A series of illuminated bargraphs corresponding to the sensors with the same 12 V or having the same
earth, indicates a fault in this source. These priorities are dealt with in the "NOTES" section of the
fault-finding of the bargraph concerned.
2 - Input / output fault bargraphs
a) Illuminated :
The fault is present : treat the fault following the method described in the "INTERPRETATION OF XR25
BARGRAPHS" section.
b) Flashing :
Note the bargraphs displayed on the XR25.
Erase the memory of the computer and attempt to re-illuminate the bargraph: ignition on, idle speed
(or at starter speed) or by means of a road test (the "NOTES" section in the fault finding for the
bargraph concerned may help to determine the conditions under which the bargraph will illuminate).
If the bargraph has re-illuminated (fixed or flashing) :
The fault is present once again. In this case, treat the fault bargraph.
If the bargraph has not re-illuminated, check :
- the electrical lines which correspond to the flashing fault,
- the connectors of these lines (for rust, bent pins...).
- the resistance of the component found to be faulty.
- the cleanliness of the wires (insulation melted or cut, friction..).
NOTE : If the customer complaint does not correspond to the fault bargraph which is flashing
(example : Air temperature sensor fault bargraph flashing, but no customer complaint) ignore
this memorised fault and erase it.
3 - No bargraphs illuminated
If no bargraphs are illuminated on the XR25, carry out a status and parameter check. This may help in
detecting a problem.
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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
1Dialogue
with XR25D13
(selector on
S8)Fault test
9.NJ
Use fiche 27
Code present
Deal with
fault
bargraph
2Change to
status testG01*
10.NJ
Status testNone
3Battery
voltage# 0411.8 < X < 13.2 V
DIAG 1
4Computer
configurationComputer configured to
manual gearbox
Computer configured to
automatic transmissionSee Fiche
"Reminder C"
to configure
vehicle
5Immobiliser Ignition onThis status bargraph must
be extinguished when
the ignition is on to
indicate that the
immobiliser is not active.
DIAG 12
1
19
19
1
1
3
17-30
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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
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INJECTION
Fault finding - Status and parameter checks
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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
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JF5111.0
INJECTION
Fault finding - Status and parameter checks
17
E7J 780
engine
Order of
operationsFunction to be
checkedAction Bargraph Display and notes Fault finding
1Charging
circuit# 0413 < X < 14.5 V
DIAG 1
2Throttle
potentiometerNo loadIlluminated (does not
flash!)DIAG 2
3 Idle speed
regulation# 06
# 12
# 21700 < X < 800 rpm
2 % < X < 15 %
- 2.4 % < X < 6.2 %DIAG 7
4Anti-pinking
circuit# 13 (at
3500 rpm,
no load)X variable and not zeroDIAG 8
5 Pressure circuit# 01
# 16300 ≤ X ≤ 400 mb
X = atmospheric pressureDIAG 9
6Richness
regulation# 35
# 050 < X < 255
X varies around 128
50 ≤ X ≤ 900 mb
DIAG 10
See also
DIAG 15
7Fuel pressureConnect a
pressure
gauge to the
gallery and
activate the
starter
motorPressure gauge must
show
2.5 barsFuel pressure,
see Workshop
Repair
Manual or
section
Carry out the actions below (engine warm, at idle speed, no consumers)
if the engine starts.
Otherwise refer to the previous pages.
NOTES
6
6
2
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INJECTION
Fault finding - Status and parameter checks
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E7J 780
engine
Order of
operationsFunction to be
checkedAction Bargraph Display and notes Fault finding
8ACAC selected
# 06Illuminated when AC
selected
Illuminated when AC
requests compressor
operation
Illuminated when
injection authorises
operation of compressor
830 < X < 930 rpm
DIAG 16
9Power assisted
steering
pressostatTurn 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
17-34