Page 316 of 363

v0406.0
IMMOBILISER
Fault finding - Fault Chart (petrol version) 82
AFTER REPAIRCarry out a conformity check.
Check that the immobiliser system is working correctly.
Erase fault memory G0**.
Fault Chart 3IMMOBILISER WARNING LIGHT REMAINS PERMANENTLY ILLUMINATED
(even with ignition off) OR REMAINS PERMANENTLY EXTINGUISHED
Check that decoder unit programming has been correctly carried out.NOTES
no Replace the fuse.
yes
Check the condition of the +before ignition
fuse.
Is the fuse in good condition?
no Carry out petrol configuration G22*1*.
yes
no
Refer to the chart for bargraph 5LH in the
section "Fault finding - Interpretation of
XR25 bargraphs ".
Check that bargraph 3RH is extinguished .
Is bargraph 3RH extinguished ?
yes
no Repair the wiring.
Check continuity and insulation from earth
of the wiring between track A5 of the 18
track decoder unit connector and the
instrument panel .
Is the wiring in good condition?
Check that bargraph 5LH is extinguished .
Is Bargraph 5LH extinguished ?
yes
A
82-19
Page 323 of 363

v0406.0
IMMOBILISER
Fault finding - Fault Chart (diesel version)82
AFTER REPAIRWhen communication has been established, deal with any illuminated fault
bargraphs.
Carry out a conformity check.
Fault Chart 1NO XR25/COMPUTER COMMUNICATION
Lines K and L are shared between several computers, which can disrupt them. If
the fault persists, it would be prudent to check that they are not disrupting lines K
and L.
NOTES
Ensure that the XR25 is not the cause of the fault by trying to communicate with another computer on the
vehicle (air conditioning computer, injection computer ...).
Check that the ISO selector is on position S8 , that you are using the latest XR25 cassette and the correct
access code (D56).
Check the battery voltage (U > 10.5 volts). Recharge the battery if necessary.
Ensure that the diagnostic socket is correctly fed.
Check and ensure the continuity and insulation of the wiring of tracks A3 and A4 of the decoder unit
connector.
If there is still no dialogue between the XR25 and the decoder unit , replace the decoder unit .
Check that the 18 track decoder unit connector is correctly connected.
Check that the decoder unit is correctly fed :
-earth on track A8 of the decoder unit connector
-+ before ignition feed on track A9 of the decoder unit connector.
Check the condition of the +before ignition fuse.
Replace the fuse if necessary.
82-26
Page 324 of 363

v0406.0
IMMOBILISER
Fault finding - Fault Chart (diesel version)82
AFTER REPAIRCarry out a conformity check.
Check that the immobiliser system is working correctly.
Erase fault memory G0**.
Fault Chart 2IGNITION ON, IMMOBILISER WARNING LIGHT FLASHES
PERMANENTLY (impossible to start)
None.NOTES
no See Fault Chart 1.
Switch on the ignition.
Connect the XR25. Use fiche n° 56, selector
on S8. Enter D56.
Is there communication between the XR25
and the decoder unit?
yes
no Replace the fuse if necessary.
yes
Check the condition of the antenna ring.
Is the fuse in good condition?
no
Refer to the chart for bargraph 4RH in the
section "Fault finding -Interpretation of
XR25 bargraphs ".
yes
no Carry out the programming operation if the
unit is new , otherwise, replace the decoder
unit .
Switch on the ignition and check that
bargraph 4RH is illuminated .
Is Bargraph 4RH illuminated?
yes
A
Switch on the ignition and check that
bargraph 19RH is extinguished .
Is Bargraph 19RH extinguished ?
82-27
Page 329 of 363

v0406.0
IMMOBILISER
Fault finding - Fault Chart (diesel version)82
AFTER REPAIRCarry out a conformity check.
Check that the immobiliser system is working correctly.
Erase fault memory G0**.
Fault Chart 5IMMOBILISER WARNING LIGHT REMAINS PERMANENTLY ILLUMINATED (even
when ignition turned off ) OR REMAINS PERMANENTLY EXTINGUISHED
Check that decoder unit programming has been properly carried out.NOTES
no Replace the fuse.
yes
Check the condition of the +before ignition
fuse.
Is the fuse in good condition?
no Repair the wiring.
yes
Check continuity and insulation from earth
of the wiring between track A5 of the 18
track decoder unit connector and the
instrument panel .
Is the wiring in good condition?
Carry out the following tests to determine the
faulty component :
- If the immobiliser warning light is
illuminated , disconnect the 18 track
decoder unit connector and check that
the immobiliser warning light
extinguishes,
- If the immobiliser warning light is
extinguished , connect track A5 of the
decoder unit connector to a vehicle earth
and check that the immobiliser warning
light illuminates.
Does the immobiliser warning light
illuminate correctly during the test?
no Replace the instrument panel .
Replace the decoder unit .
yes
yes
Check that bargraph 5LH is extinguished .
Is bargraph 5LH extinguished ?no
Refer to the chart for bargraph 5LH in the
section "Fault finding - Interpretation of
XR25 bargraphs "
82-32