Page 49 of 57
38C-49
AFTER REPAIRClear the computer memory using command RZ001 Fault memory.
Carry out a road test followed by another check with the diagnostic tool.
V1 MR-376-X76-38C000$170.mif
ANTI-LOCK BRAKING SYSTEM
Fault finding – Fault Finding Chart38C
ABS BOSCH 8.1
Vdiag No.: 18
ALP3 Pull
NOTESOnly address this customer complaint after a complete check with the diagnostic
tool.
Disconnect one wheel speed sensor.
Start the engine and ensure that only the ABS fault warning light comes on. Do not drive the vehicle if the brake
fault warning light is also illuminated because the "braking compensator" function is no longer guaranteed.
Carry out a road test with the ABS thus out of order.
Is the fault still present under these conditions?
Raise the vehicle so that you can rotate the wheels and check:
– whether the speed sensors have been incorrectly
connected,
– whether the pipes on the hydraulic unit have been inverted.
For these two tests, consult and apply the procedures defined
in ALP2 Locking of one or several wheels.
Check the condition and conformity of the ABS targets.
If the fault is still present, contact the techline.If the brake pedal travel is relatively long,
bleed the brake circuit.
If the travel is normal, check the tyre
pressures, the front axle, or for any leaks in
the circuit.
NOYES
ABS8.1X76_V18_ALP3
Page 50 of 57
38C-50
AFTER REPAIRClear the computer memory using command RZ001 Fault memory.
Carry out a road test followed by another check with the diagnostic tool.
V1 MR-376-X76-38C000$170.mif
ANTI-LOCK BRAKING SYSTEM
Fault finding – Fault Finding Chart38C
ABS BOSCH 8.1
Vdiag No.: 18
ALP4 Drift
NOTESOnly address this customer complaint after a complete check with the diagnostic
tool.
Disconnect one wheel speed sensor.
Start the engine and ensure that only the ABS fault warning light comes on. Do not drive the vehicle if the brake
fault warning light is also illuminated because the "braking compensator" function is no longer guaranteed.
Carry out a road test with the ABS thus out of order.
Is the fault still present under these conditions?
Normal behaviour linked to the system operation during
the regulation phase, mainly on surfaces with uneven
grip or which are poorly laid.Road holding fault not related to the ABS.
Check the condition of the brake linings and that
they are to specification and check the tyre
pressures, the front axle, etc.
NOYES
ABS8.1X76_V18_ALP4
Page 51 of 57
38C-51
AFTER REPAIRClear the computer memory using command RZ001 Fault memory.
Carry out a road test followed by another check with the diagnostic tool.
V1 MR-376-X76-38C000$170.mif
ANTI-LOCK BRAKING SYSTEM
Fault finding – Fault Finding Chart38C
ABS BOSCH 8.1
Vdiag No.: 18
ALP5Unexpected ABS operation at low speed and slight pedal
pressure
NOTESOnly address this customer complaint after a complete check with the diagnostic
tool. Warning: ABS control is sensitive to poor traction (icy roads, wet cobblestones,
etc.).
It is possible to feel brake pedal vibrations which are associated with the reaction of the system in particular
circumstances, such as:
– crossing rumble strips,
– tight cornering with lifting of the inside rear wheel.
These vibrations may be linked to simple brake limiter activation, when the pressure on the rear axle is limited.
If the fault is different, check the speed sensor connectors (micro-breaks).
ABS8.1X76_V18_ALP5
Page 52 of 57
38C-52
AFTER REPAIRClear the computer memory using command RZ001 Fault memory.
Carry out a road test followed by another check with the diagnostic tool.
V1 MR-376-X76-38C000$170.mif
ANTI-LOCK BRAKING SYSTEM
Fault finding – Fault Finding Chart38C
ABS BOSCH 8.1
Vdiag No.: 18
ALP6 Unexpected ABS system intervention on a poor road surface
NOTESOnly address this customer complaint after a complete check with the diagnostic
tool.
On poor road surfaces it is normal to feel hesitation and vibrations of the pedal as well grating which is more
significant than on good surfaces.
This gives the impression of a variation in efficiency, but this should be considered normal.
ABS8.1X76_V18_ALP6
Page 53 of 57
38C-53
AFTER REPAIRClear the computer memory using command RZ001 Fault memory.
Carry out a road test followed by another check with the diagnostic tool.
V1 MR-376-X76-38C000$170.mif
ANTI-LOCK BRAKING SYSTEM
Fault finding – Fault Finding Chart38C
ABS BOSCH 8.1
Vdiag No.: 18
ALP7Unexpected ABS operation when using special equipment (car
phone, CB, etc.)
NOTESOnly address this customer complaint after a complete check with the diagnostic
tool.
Check that the equipment which is causing the fault is approved.
Check that this equipment has been correctly installed without modification to the original wiring, particularly that
of the ABS (unauthorised earth and + after ignition feed connections on the ABS).
ABS8.1X76_V18_ALP7
Page 54 of 57
38C-54
AFTER REPAIRClear the computer memory using command RZ001 Fault memory.
Carry out a road test followed by another check with the diagnostic tool.
V1 MR-376-X76-38C000$170.mif
ANTI-LOCK BRAKING SYSTEM
Fault finding – Fault Finding Chart38C
ABS BOSCH 8.1
Vdiag No.: 18
ALP8Extension of brake pedal travel following a regulation phase (with
an irregular pedal when entering regulation).
NOTESOnly address this customer complaint after a complete check with the diagnostic
tool.
Air transit from the hydraulic unit regulation channels to the brake circuits.
Bleed the circuits following the recommended procedure in MR 374, Mechanical, 30A, General information,
Braking circuit: Bleeding (use of diagnostic tool command modes).
After the operation, carry out a road test with ABS regulation.
If the fault persists, carry out the above operation again once or twice.
If the customer complaint is particularly pronounced, and the bleeds have not rectified it, contact the Techline.
ABS8.1X76_V18_ALP8
Page 55 of 57
38C-55
AFTER REPAIRClear the computer memory using command RZ001 Fault memory.
Carry out a road test followed by another check with the diagnostic tool.
V1 MR-376-X76-38C000$170.mif
ANTI-LOCK BRAKING SYSTEM
Fault finding – Fault Finding Chart38C
ABS BOSCH 8.1
Vdiag No.: 18
ALP9 Spongy pedal
NOTESOnly address this customer complaint after a complete check with the diagnostic
tool.
Air in the brake circuits.
Bleed the circuits in the conventional way starting with the rear right-hand brake, followed by rear left-hand, front
left-hand, and finally the front right-hand. Repeat the operation if necessary.
Check the play of the front and rear bearings.
ABS8.1X76_V18_ALP9
Page 56 of 57
38C-56
AFTER REPAIRClear the computer memory using command RZ001 Fault memory.
Carry out a road test followed by another check with the diagnostic tool.
V1 MR-376-X76-38C000$170.mif
ANTI-LOCK BRAKING SYSTEM
Fault finding – Fault Finding Chart38C
ABS BOSCH 8.1
Vdiag No.: 18
ALP10 Brake pedal vibration
NOTESOnly address this customer complaint after a complete check with the diagnostic
tool.
Normal reaction of the brake pedal during an ABS regulation phase or pressure limitation on the rear axle (brake
limiter function).
ABS8.1X76_V18_ALP10
