B76531.0
ELECTRONICALLY CONTROLLED HYDRAULIC SYSTEMS
Fault finding - Interpretation of XR25 bargraphs
38
ABS BOSCH
5.3
Erase computer memory(GO**).
Carry out a road test followed by a check with the XR25 kit.AFTER REPAIR
Bargraph 7 left hand side illuminated
Rear left wheel sensor circuit
7
None.
NOTES
Fiche n° 53
If all checks are correct, reconnect the computer and wheel speed sensor, then erase the computer
memory.
Exit fault finding mode(G13*) and switch off the ignition.
Switch on the ignition and replace the sensor if the fault reappears.
If the fault reappears after replacing the sensor, replace the computer.
Check the connection and condition of the sensor connections.
Check the connections at the intermediate connection under the body (R101).
If the connector is correct, check the resistance of the sensor at its connector. Replace the sensor if the
resistance is not approximately 1.6 Kohms (1.6 Kohms ± 320 ohms).
If the resistance is correct, check and ensure the continuity of the connections between the sensor
connector and the computer connector :
- between one track of the sensor connector and track 8 of the computer connector (via track B of the
connector under the body R101),
- between the other track of the sensor connector and track 9 of the computer connector (via track A of
the connector under the body R101).
Also check the insulation between these connections.
Carry out a visual inspection of the sensor wiring and check the quality of the connections on the 31 track
computer connector.
38-9
B76531.0
ELECTRONICALLY CONTROLLED HYDRAULIC SYSTEMS
Fault finding - Interpretation of XR25 bargraphs
38
ABS BOSCH
5.3
Erase computer memory(GO**).
Carry out a road test followed by a check with the XR25 kit.AFTER REPAIR
Bargraph 7 Right hand side illuminated
Rear right wheel sensor circuit
7
None.
NOTES
Fiche n° 53
If all checks are correct, reconnect the computer and the wheel speed sensor, then erase the computer
memory.
Exit fault finding mode(G13*) and switch off the ignition.
Switch on the ignition and replace the sensor if the fault reappears.
If the fault reappears after replacing the sensor, replace the computer.
Check the connection and condition of the sensor connections.
Check the connections at the intermediate connector under the body (R101).
If the connector is correct , check the resistance of the sensor at its connector.
Replace the sensor if its resistance is not approximately 1.6 Kohms (1.6 Kohms ± 320 ohms).
If the resistance is correct, check and ensure the continuity of the connections between the sensor
connector and the computer connector :
- between one track of the sensor connector and track 1 of the computer connector (via track D of the
connector under the body R101),
-between the other track of the sensor connector and track 2 of the computer connector (via track C of
the connector under the body R101).
Also check the insulation between these connections.
Carry out a visual inspection of sensor wiring and check the quality of the connections on the 31 track
computer connector.
38-10
B76531.0
ELECTRONICALLY CONTROLLED HYDRAULIC SYSTEMS
Fault finding - Interpretation of XR25 bargraphs
38
ABS BOSCH
5.3
Erase computer memory(GO**).
Carry out a road test followed by a check with the XR25 kit.AFTER REPAIR
Bargraph 8 right or left hand side flashing
Front right or front left wheel sensor signal
Even if they are present at time of testing, these faults will always be declared by
BG 8 flashing on the left or right hand side.
To confirm their presence and therefore the need to apply the fault finding be-
low, carry out a road test. The fault is present if the bargraph illuminates during
the test.
If bargraphs 6 and 8 left hand side are both illuminated, deal with bargraph 6
first.
If bargraphs 6 and 8 right hand side are both illuminated, deal with bargraph 6
first.
NOTES
Fiche n° 53 8
Check the quality of the wheel speed sensor mounting (its position and that it is tightened to
recommended torque).Check the sensor / target air gap over one wheel revolution : 0.13 mm < air
gap< 1.96 mm. Check conformity of the target (condition, number of
teeth=26)
Carry out a visual inspection of the sensor wiring and check the quality of the connections on the 31 track
computer connector.
If all checks are correct, reconnect the computer and the wheel speed sensor, then erase the computer
memory.
Leave fault finding mode(G13*) and carry out a road test. Replace the sensor if the fault reappears.
If the fault reappears after replacing the sensor, it may be caused by an operating fault on a solenoid
valve and it is therefore necessary to carry out the hydraulic check of the solenoid valves with the XR25 kit
with command G03* or G04* (consult the section "Aid"). If the ten unlocking/locking cycles do not occur
on one of the wheels, replace the hydraulic assembly.
If the hydraulic assembly is not at fault, replace the computer.
Check the connection and condition of the sensor connections.
If the connector is correct , check the resistance of the sensor at its connector.
Replace the sensor if its resistance is not approximately 1.6 Kohms (1.6 Kohms ± 320 ohms).
38-11
B76531.0
ELECTRONICALLY CONTROLLED HYDRAULIC SYSTEMS
Fault finding - Interpretation of XR25 bargraphs
38
ABS BOSCH
5.3
Erase computer memory(GO**).
Carry out a road test followed by a check with the XR25 kit.AFTER REPAIR
Bargraph 9 right or left hand side flashing
Signals to rear right or rear left wheel sensor
Even if present at time of test, these faults will always be declared by BG9 flas-
hing on the left or right hand side.
To confirm their presence and therefore the need to apply the fault finding be-
low, carry out a road test.The fault is present if the bargraph illuminates during
the test.
If bargraphs 7 and 9 left hand side are both illuminated, deal with bargraph 7
first.
If bargraphs 7 and 9 right hand side are both illuminated, deal with bargraph 7
first.
NOTES
Fiche n° 53 9
Check the quality of the wheel speed sensor mounting (position and torque tightening).
Check the connection and condition of the sensor connections.
Check the connections at the intermediate connector under the body R101.
If the connector is correct , check the resistance of the sensor at its connector.
Replace the sensor if its resistance is not approximately 1.6 Kohms (1.6 Kohms ± 320 ohms).
Carry out a visual inspection of the sensor wiring and check the quality of the connections on the 31 track
computer connector.
If all checks are correct, reconnect the computer and the wheel speed sensor, then erase the computer
memory. Leave fault finding mode(G13*) and carry out a road test.
If the fault reappears, check the sensor/target air gap over one wheel rotation :
0.03 mm < air gap< 2.4 mm (test only possible on vehicle with 4 bar rear axle).
Check conformity of the target:condition, number of teeth = 26.
If the fault reappears after replacing sensor, it could be caused by a solenoid valve operating fault. It is
therefore necessary to carry out a hydraulic test of the solenoid valves with the XR25 kit with command
G05* or G06* (consult section"Aid"). If the ten unlocking/locking cycles do not occur on one of the
wheels, replace the hydraulic assembly.
If the hydraulic assembly is not at fault, replace the computer.
If all checks are correct, leave fault finding mode(G13*) and carry out a road test.
Replace the sensor if the fault reappears.
38-12
B76531.0
ELECTRONICALLY CONTROLLED HYDRAULIC SYSTEMS
Fault finding - Interpretation of XR25 bargraphs
38
ABS BOSCH
5.3
Erase computer memory(GO**).
Carry out a road test followed by a check with the XR25 kit.AFTER REPAIR
Bargraph 11 left hand side illuminated
Solenoid valve power supply fault
11Fiche n° 53
If all the checks are correct, reconnect the computer then erase its memory with command G0**.
Leave fault finding mode(G13*) and carry out a road test. Replace the computer if the fault reappears.
Carry out operations necessary for obtaining correct voltage between tracks 19 and 17/18 of the 31-track
ABS computer connector (9.4 volts < correct voltage < 17.4 volts) :
- Check tightness and condition of battery terminals.
- Check the 60A fuse in the engine connection unit (white base).
- Ensure continuity between the 60A fuse and tracks 17 and 18 of the computer connector.
- Check the ABS earths (tightening of the two earth bolts above the hydraulic assembly).
- Check/ ensure continuity between the ABS earth and track 19 of the computer connector.
None.
NOTES
38-14
B76531.0
ELECTRONICALLY CONTROLLED HYDRAULIC SYSTEMS
Fault finding - Interpretation of XR25 bargraphs
38
ABS BOSCH
5.3
Erase computer memory(GO**).
Carry out a road test followed by a check with the XR25 kit.AFTER REPAIR
Bargraph 12 right hand side flashing
Target of one of the wheels
12Fiche n° 53
Even if present at moment of testing, this fault will always be declared by BG 12
RH side flashing.
To confirm its presence and therefore the need to apply the fault finding below,
carry out a road test. The fault is present if the bargraph illuminates during the
test.
NOTES
Check the quality of wheel speed sensor mountings (position and that they are tightened to the
recommended torque).
Check the conformity of the targets :condition, number of teeth= 26.
38-16
B76531.0
ELECTRONICALLY CONTROLLED HYDRAULIC SYSTEMS
Fault finding - Interpretation of XR25 bargraphs
38
ABS BOSCH
5.3
AFTER REPAIR
13Fiche n° 53
Bargraph 13 left hand side extinguished, brake pedal depressed
Carry out checks only if illumination of the bargraph is not consistent with the
pedal position. NOTES
Bargraph 13 right and left
Brake pedalIlluminated on left hand side if pedal depressed.
Illuminated on right hand side if pedal not depressed.
BG 13 right remains permanently illuminated.
If brake lights are operating
:
- Ensure continuity between dashboard / rear left R2 connector on track 7 and track 14 of the ABS
computer connector .
Dashboard / ABS R36 intermediate connector (track 8).
If brake lights are not operating
:
- Check condition and adjustment of brake light switch as well as the 15A fuse for the brake lights (in
the passenger compartment connection unit). Replace if necessary.
- Disconnect the brake light switch, then check / ensure presence of + after ignition feed on track A3
of the connector
- Check operation of brake light switch (closed contact between tracks A3 and B1).
- Check and ensure continuity between track B1 of the brake light switch connector and the dashboard
/ rear left hand side R2 connector on track 7.
Bargraph 13 permanently illuminated on left hand side
- Check the condition and adjustment of the brake light switch. Replace if necessary.
- Check the operation of the brake light switch contact (closed contact between tracks A3 and B1).
Replace the brake light switch if there is permanent continuity between the two tracks.
- Check and ensure insulation from 12 volts of the connection between track B1 of the brake light
switch connector and track 14 of the ABS computer connector .
Intermediate connectors : Dashboard / ABS R36 on track 8.
Dashboard / rear left hand side R2 on track 7.
Carry out a road test followed by a check with the XR25 kit.
38-17
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
ABS WARNING LIGHT DOES NOT ILLUMINATE FOR 3
SECONDS WHEN IGNITION SWITCHED ONFault chart 1
Only consult this section after a complete check with the XR25 kit.NOTES
Check condition of ABS warning light bulb
and its power supply.
Ensure continuity of connection between
track 21 of the computer connector and the
warning light (track 3 of the black
instrument panel connector).
If fault persists, check the instrument panel
operation.
Carry out an inspection of the connections
on the 31 track connector.
Replace the computer if the fault persists.
no
Check the 15A instrument panel fuse on the
passenger compartment connection unit
(if the problem affects all instrument panel
operations).
Turn off the ignition.
Disconnect the computer, then switch on
the ignition again.
Does the warning light illuminate?
38-21