Page 285 of 363

B76531.0
ELECTRONICALLY CONTROLLED HYDRAULIC SYSTEM
Fault finding - Fault chart 38
ABS BOSCH
5.3
AFTER REPAIR Carry out a road test, then a check with the XR25 kit.
LOCKING OF ONE OR MORE WHEELSFault chart 4
REMINDER:Wheel locking on a vehicle equipped with ABS, or tyre squeal, considered by the customer
as locking, can be linked to a normal reaction of the system and should not be systematically
considered as a fault :
- locking is allowed below 3.75 mph ( 6 km/h) (the system will not provide regulation).
- Braking with ABS regulation under very bad road conditions (high degree of tyre squeal).
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Only consult this section after a complete check with the XR25 kit.NOTES
On the other hand, if there really is wheel locking on one or more wheels, lift the vehicle so the wheels can
be turned, and check :
- a possible incorrect connection in the speed sensor connection.
• Use operations #01, #02, #03 and #04 while turning the appropriate wheel and ensure the consis-
tency of the results obtained .
• If the value measured is zero, turn the other wheels to confirm a bad electrical connection of the sen-
sors and repair the wiring.
- A possible incorrect connection of the hydraulic assembly pipes.
• Use operations G03*, G04*, G05* and G06* while applying the brake and check for the ten cycles of
unlocking/locking on the wheel concerned (consult section "Aid").
• If the ten cycles do not occur on the wheel tested, (wheel remains locked), see if they occur on ano-
ther wheel (if a bad connection is confirmed: repair).
• If the ten cycles do not occur on a wheel and the pipes are correctly connected, replace the hydraulic
assembly.
• Check the condition of the ABS targets and that they conform.
• Also check the sensor/target air gap by rotating each of the wheels :
Front 0.13 mm < air gap over one rotation < 1.96 mm.
Rear 0.03 mm < air gap over one rotation < 2.4 mm (check only possible on vehicles with four-bar
rear axles).
If the fault persists after these checks, replace the hydraulic assembly.
38-24
Page 286 of 363

B76531.0
ELECTRONICALLY CONTROLLED HYDRAULIC SYSTEM
Fault finding - Fault chart 38
ABS BOSCH
5.3
AFTER REPAIR Carry out a road test, then a check with the XR25 kit.
yes
PULLINGFault chart 5
Only consult this section after a complete check with the XR25 kit.NOTES
Lift the vehicle so the wheels can be turned
and check for :
- a possible incorrect connection in the
speed sensors,
- a possible incorrect connection of the
hydraulic assembly piping.
For these two checks, consult and apply the
methods defined in Fault Chart 4.Check the
condition of the ABS targets and that they
conform. Also check the sensor/ target air
gap by rotating each wheel.
If the fault persists, replace the hydraulic
assembly.
If the pedal travel is relatively long, bleed
the brake circuit.
If it is normal, check the tyre pressure, the
front axle assembly
or possibly for leaks in the circuit.
no
Remove the 10A ABS fuse on the passenger
compartment connection unit and carry out
a road test with the ABS non-operational.
Does the fault persist under these
conditions?
38-25
Page 288 of 363
B76531.0
ELECTRONICALLY CONTROLLED HYDRAULIC SYSTEM
Fault finding - Fault chart 38
ABS BOSCH
5.3
AFTER REPAIR Carry out a road test, then a check with the XR25 kit.
UNEXPECTED ABS OPERATION AT LOW SPEEDS AND
WHEN LITTLE PRESSURE APPLIED TO BRAKE PEDALFault chart 7
It is possible to feel brake pedal vibrations which are linked to reactions of the system in particular
situations :
- Crossing speed bumps.
- Rear inside wheel lifts on tight bends.
If the problem is different, check the speed sensors connectors ( micro-breaks) as well as the air gaps.
Only consult this section after a complete check with the XR25 kit.NOTES
38-27
Page 305 of 363

v0406.0
IMMOBILISER
Fault finding- Interpretation of XR25 Bargraphs 82
Erase the memorised fault by entering GO** on the XR25 keyboard.
Carry out a conformity check.
Check operation of the immobiliser system.AFTER REPAIR
Bargraph 6 left hand side illuminated
DIESEL SOLENOID VALVE CLEARANCE
6
Check that the computer configuration is correct :
- diesel : Bargraph 3 right hand side illuminated
- petrol : Bargraph 3 right hand side extinguishedNOTES
Fiche n° 56
Set the XR25 to pulse sensor mode (button "G", input on terminal "Vin").
Ignition on, check for pulses on track A6 of the 18 track decoder unit connector (test with the decoder
unit and the coded electronic unit of the solenoid valve connectors connected).
Ignition on, if there are no pulses, change the decoder unit.
Switch on the ignition for 30 consecutive seconds, then switch off the ignition and wait until the
immobiliser warning light flashes (immobiliser active).
Switch on the ignition again and check that bargraph 8 left hand side is permanently illuminated.
Is Bargraph 8 left hand side permanently illuminated ?
Replace the decoder unit.YES
NOReplace the solenoid valve coded electronic unit.
82-8
Page 306 of 363

v0406.0
IMMOBILISER
Fault finding- Interpretation of XR25 Bargraphs 82
Erase the memorised fault by entering GO** on the XR25 keyboard.
Carry out a conformity check.
Check operation of the immobiliser system.AFTER REPAIR
Bargraphs 6 left and 6 right hand side illuminated
ACCEPTANCE (CLEARANCE) OF THE SIGNAL BY THE DIESEL
SOLENOID VALVE AND CODED LINE
6
Before beginning the fault finding, switch on the ignition for longer than 30
consecutive seconds, then switch off the ignition.NOTES
Fiche n° 56
Ensure that the connector of the coded electronic unit of the solenoid valve is properly connected.
Set the XR25 to pulse sensor mode (button "G", input on terminal "Vin").
Ignition on, check for pulses on track A6 of the decoder unit connector (test with decoder unit and
solenoid valve coded electronic unit connectors connected).
Are there any pulses?
Replace the solenoid valve side electronic unit.YES
NOReplace the decoder unit.
For the diesel version, if bargraphs 6 right and 6 left are illuminated, check the impact switch.
Check the condition of the electrical wiring between track A6 of the decoder unit and track 8 of the
coded solenoid valve connector and check the 12 Volts supply and earth.
Repair if necessary.
82-9
Page 307 of 363
v0406.0
IMMOBILISER
Fault finding- Interpretation of XR25 Bargraphs 82
AFTER REPAIR
Bargraph 6 right hand side illuminated
CODED LINE
6
NONE.NOTES
Fiche n° 56
Check the continuity and insulation from earth and from 12 volts of the wiring between track A6 of the
18 track decoder unit connector and track ** of the injection computer .
Repair the wiring if necessary.
Set the XR25 to pulse sensor mode (button "G", input on terminal "Vin").
Ignition on, check for pulses on track A6 of the decoder unit connector (test with decoder unit and
solenoid valve coded electronic unit connectors connected).
Are there any pulses ?
Replace the injection computer.YES
NOReplace the decoder unit.
** track : 43 or 19 depending on engine
Erase the memorised fault by entering GO** on the XR25 keyboard.
Carry out a conformity check.
Check operation of the immobiliser system.
For petrol vehicles, if bargraph 6 right hand side is illuminated, check the impact switch.
82-10
Page 308 of 363

Check the continuity and insulation with earth and 12 volts of the wiring between :
18 track decoder unit connector (A2 4) antenna ring
Repair the wiring if necessary.
v0406.0
IMMOBILISER
Fault finding- Interpretation of XR25 Bargraphs 82
AFTER REPAIR
Bargraph 7 right hand side illuminated or flashing
ANTENNA RING/DECODER UNIT CONNECTION
XR25 aid: *27 = cc.1 short circuit+ 12 volts
co.0 open circuit
7
None.NOTES
Fiche n° 56
Ignition off, check for + 12 volts on track A2 of the decoder unit connector, wiring side (decoder
connector disconnected and antenna ring connector connected).
If 12 volts + before ignition feed are not measured, replace the +before ignition feed fuse
If the problem persists, replace the antenna ring.
Check that the antenna ring is properly fed with earth on track 2 and 12 Volts on track 3.
Disconnect the 4 track antenna ring connector.
Set the XR25 to pulse sensor mode (button "G", input on terminal "Vin").
When switching the ignition on again, check for a pulse on track A2 of the 18 track decoder unit
connector (test with decoder unit and antenna ring connectors connected).
When the ignition is switched on, is there a pulse?
Replace the antenna ring.YES
NOReplace the decoder unit.
Erase the memorised fault by entering GO** on the XR25 keyboard.
Carry out a conformity check.
Check operation of the immobiliser system.
82-11
Page 309 of 363

Check the insulation in relation to the earth of the wiring between :
B1 B2
PLIP
decoder unit B2 B3 central locking
B5 A1 button
Are they insulated from earth ?
v0406.0
IMMOBILISER
Fault finding- Interpretation of XR25 Bargraphs 82
AFTER REPAIR
Bargraph 11 left hand side remains extinguished
after pressing the PLIP
PLIP SIGNAL RECEIVED
11
If BG 17right is illuminated, do not apply the following fault finding as the
decoder unit is new. Carry out the Plip programming procedure.
Only consult the following fault finding if BG 11 left remains extinguished after
having tried to lock or unlock the vehicle doors with the PLIP .
NOTES
Fiche n° 56
Check if locking or unlocking the doors is possible by testing with the other key. If locking or unlocking of
the vehicle doors is possible, replace the battery in the first key.
On the infrared transmitter connector, check for + 12 V before ignition feed between tracks B2 and A3.
Is this voltage present ?
Set the XR25 to pulse sensor mode (button "G", input on terminal "Vin").
Check for pulses on track B2 of the infrared transmitter by pressing the PLIP (test
with the decoder unit and infrared transmitter connectors connected).
Are there any pulses when the PLIP is pressed?YES
YES Replace the decoder unit.
NO Replace the infrared transmitter.
NO
YES Repair the faulty wiring.
NO Change the decoder unit.
Carry out a conformity check.
Check operation of the immobiliser system.
82-12