DPCF01 1.0
LUCAS DIESEL INJECTION
Fault finding - Interpretation of XR25 bargraphs13
AFTER REPAIR
Bargraphs 18 and 19 RH and LH
Computer configuration for with and without air conditioning/
with and without power assisted steering pump assembly
18
Vehicles fitted with power assisted steering but without air conditioning must
be configured to "without PAS".NOTES
These bargraphs show the computer configuration for the air conditioning and pump assembly power
assisted steering options.
Computers sold by the Parts Department are systematically configured for vehicles with air conditioning
and with the PAS pump assembly.
If the vehicle does not have air conditioning, use the command mode G50*4* to reverse the computer
configuration (the opposite command exists for configuring to "with AC": G50*3*).
If the vehicle is not fitted with a PAS pump assembly (vehicle without air conditioning), use command
mode G50*9* to reverse the computer configuration (the opposite command exists for configuring to
"with PAS": G50*8*).
NOTE : Vehicles fitted with power assisted steering but without air conditioning must be configured to
"without PAS".
19
Erase the computer memory (G0**), switch the ignition off, then carry out a road
test.
Finish the operation by checking using the XR25.
13-30
DPCF01 1.0
LUCAS DIESEL INJECTION
Fault finding - Aid
13
REPLACING THE COMPUTER
A)On these computers it is necessary to programme the load lever full load position (this value is required to
replace and adjust the load lever position potentiometer).
Programming procedure:
• Enter code G31* on the XR25 (engine speed zero)
• Press the accelerator pedal until the display flashes
"PF".
The display then shows "bon", "Fin" then "6/7.dlE" when the procedure has been carried out correctly.
Bargraph 12 RH side must be extinguished.
• Switch off the ignition.
B)Lucas digital DPC injection computers are sold pre-configured to "with air conditioning".
If the vehicle does not have air conditioning, use command G50*4* on the XR25 to programme "without
air conditioning".
Lucas digital DPC injection computers are sold pre-configured to "with power assisted steering" (with po-
wer assisted steering pump assembly).
If the vehicle does not have a power assisted steering pump assembly (vehicle without air conditioning),
use command G50*9* on the XR25 to programme "without power assisted steering".
Vehicles fitted with power assisted steering but without air conditioning must be configured to "without
power assisted steering".
REPLACING THE LOAD LEVER POSITION POTENTIOMETER
The load lever position potentiometer may only be replaced in After Sales if the full load position has been
programmed into the computer before the fault with the potentiometer.
Procedure for replacing and adjusting the load lever position potentiometer:
• Fit the new potentiometer into position without locking the mounting bolts.
• Connect the potentiometer and set up the XR25 (S8 code D34).
• Start command G32* on the XR25, keep the accelerator pedal fully depressed (do not touch the load lever
directly) and turn the potentiometer until the display on the XR25 shows a value other than H.L (outside li-
mits). Adjust the setting by turning the potentiometer to obtain 0 on the display.
• Tighten the mounting bolts with the potentiometer in this position then press * to complete the adjus-
tment procedure.
13-31
DPCF01 1.0
LUCAS DIESEL INJECTION
Fault finding - Checking conformity
13
Engine cold, ignition onNOTES
Order of
operationsFunction to check Action Bargraph Display and notes
1 Dialogue with XR25D34
(selector on
S8) 6. dlE
Use fiche n° 60
fault test side
2Interpretation of
normally illuminated
bargraphs Fault test
Code present
3 Change to status test
modeG01* 7. dlE
Use fiche n° 60
status test side
4 Interpretation of
normally illuminated
bargraphs
Code present
Advance corrector fed
Illuminated if command mode
G0** has been used since the
last dialogue took place
Fault warning light fed
Illuminated in preheating
phase
Injection computer may give
load lever position to other
computers (not used)
Injection computer may give
engine speed information to
other computers (not used)
1
1
1
2
11
4
11
10
10
13-32
DPCF01 1.0
LUCAS DIESEL INJECTION
Fault finding - Checking conformity
13
Engine cold, ignition onNOTES
Order of
operationsFunction to check Action Bargraph Display and notes
5Computer
configuration
With AC
Without ACG50*3*
G50*8*
G50*4*
G50*9*With AC
With PAS with pump
Without AC
With conventional PAS
6Absolute pressure
sensor#16 X = local atmospheric pressure
7Coolant temperature
sensor#02 X = Ambient temperature
± 5 °C
8Air temperature
sensor#03 X = Ambient temperature
± 5 °C
9EGR solenoid valve
#24 X = 0
18
18
19
19
13-33
DPCF01 1.0
LUCAS DIESEL INJECTION
Fault finding - Fault charts
13
AFTER REPAIR
Use bornier Elé. 1332 for any operations on the computer connector.NOTES
Chart 1NO DIALOGUE FROM THE COMPUTER TO THE XR25.
Ensure that the XR25 is not the cause of the fault by trying to communicate with the computer on ano-
ther vehicle. If the XR25 is not the cause of the fault and dialogue is not established with another compu-
ter on the same vehicle, a faulty computer may be causing interference on the K and L fault finding lines.
Disconnect connections successively to determine which computer is at fault.
Check the ISO selector is on position S8, that you are using the latest XR25 cassette and the correct access
code (D34).
Check the battery voltage and carry out any necessary operations to ensure the correct voltage (U battery
> 10.5 volts).
Carry out a road test then check using the XR25.
Deal with any illuminated fault bargraphs.
Check the 15 Amp fuses on the engine connection unit have not blown (positions 3 and 4).
Check the connection and condition of the connections on the computer connector and the connection
R67 engine / dashboard.
Check the computer is correctly fed:
- Earth on track 2 of the computer connector (check the condition and tightness of the engine earth
strap and the engine earth on the gearbox housing).
- + after ignition feed on track 1 of the computer connector.
Check the diagnostic socket is correctly fed:
- Earth on track 5.
- + before ignition feed on track 16.
Check and ensure the continuity and insulation of the lines in the connection diagnostic socket/
computer:
- Between track 10 of the computer connector and track 15 of the diagnostic socket.
- Between track 13 of the computer connector and track 7 of the diagnostic socket.
If fault finding is not established after these operations, replace the computer (consult the "Aid" section
for this operation).
13-38
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
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.
17-3
JF5111.0
INJECTION
Fault finding - Introduction
17
E7J 780
engine
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.
17-4