Page 86 of 101
38C-86V3 MR-413-X44-38C050$170.mif
ANTI-LOCK BRAKING SYSTEM
Fault finding – Customer complaints38C
Bosch 8.1 ESP
Vdiag No.: 05
OTHER CASES
No dialogue with the ABS computer ALP1
ESP computer not detected during the multiplex network test on CLIP ALP12
Illumination of brake lights ALP 13
Unexpected ABS operation at low speeds and slight pedal pressure ALP14
Intermittent illumination of brake, ESP, ABS, SERVICE and STOP warning lights
and the message "Brake failure" on the instrument panel with no fault codes in
the computerALP15
Page 89 of 101

38C-89
AFTER REPAIRClear the computer fault memory.
Carry out a road test followed by another check with the diagnostic tool.
V3 MR-413-X44-38C050$180.mif
ANTI-LOCK BRAKING SYSTEM
Fault finding – Fault finding chart38C
Bosch 8.1 ESP
Vdiag No.: 05
ALP3 Pull
NOTESOnly consult this customer complaint after a full check with the diagnostic tool.
Check the conformity of the mechanical components (see MR 411, Mechanical,
30A, General information, Brake, Specifications).
Disconnect one wheel speed sensor.
Start the engine and check that only the ABS
and ESP fault warning lights are lit.
Is the brake fault warning light also lit?Do not drive, the "braking compensator" function
cannot be carried out (risk of a spin).
Deal first with the faults using the diagnostic tool.
Drive the vehicle and operate the brakes.
Is the customer complaint still present
under these conditions?If the brake pedal travel is comparatively long, bleed
the brake circuit (see MR 411, Mechanical, 30A,
General information, Brake circuit, Bleeding).
If the travel is normal, check that the 4 vehicle tyres
are identical and in accordance with the
manufacturer's recommendations (see MR 411,
Mechanical, 35A, Wheels and tyres, Tyre, Tyre
pressure, Identification and Tyre, Identification).
Check and adjust the wheel alignment (see MR 411,
Mechanical, 30A, General information, Front
axle, Adjustment).
Check for any leaks on the brake circuit.
Apply the fault finding procedure described in the ALP 2
"Locking of one or several wheels".
YES
NO
YES
NO
ESP_V05_ALP3
Page 90 of 101

38C-90
AFTER REPAIRClear the computer fault memory.
Carry out a road test followed by another check with the diagnostic tool.
V3 MR-413-X44-38C050$180.mif
ANTI-LOCK BRAKING SYSTEM
Fault finding – Fault finding chart38C
Bosch 8.1 ESP
Vdiag No.: 05
ALP4 Drift
NOTESOnly address this customer complaint after a complete check with the diagnostic tool.
Disconnect one wheel speed sensor.
Start the engine and check that only the ABS
and ESP fault warning lights are lit.
Is the brake fault warning light also lit?Do not drive, the "braking compensator" function
cannot be carried out (risk of a spin).
Deal first with the faults using the diagnostic tool.
Drive the vehicle and operate the brakes.
Is the customer complaint still present
under these conditions?It is a road holding fault not related to the ABS/ESP
system.
Check the condition and conformity of the front and
rear brake linings.
Check that the 4 vehicle tyres are identical and in
accordance with the manufacturer's
recommendations (see MR 411, Mechanical, 35A,
Wheels and tyres, Tyre pressure, Identification
and Tyres, Identification).
Check that the pressures of the 4 tyres conform to
the manufacturer's recommendations (see MR 411,
Mechanical, 35A, Wheels and tyres, Tyre
pressure, Identification).
Check and adjust the wheel alignment (see MR 411,
Mechanical, 30A, General information, Front
axle, Adjustment).
Normal behaviour linked to the system operation during the
regulation phase, mainly on surfaces with uneven grip or
which are poorly laid.
YES
NO
YES
NO
ESP_V05_ALP4
Page 101 of 101
38C-101
AFTER REPAIRClear the computer fault memory.
Carry out a road test followed by another check with the diagnostic tool.
V3 MR-413-X44-38C050$180.mif
ANTI-LOCK BRAKING SYSTEM
Fault finding – Fault finding chart38C
Bosch 8.1 ESP
Vdiag No.: 05
ALP15Intermittent illumination of brake, ESP, ABS, SERVICE and STOP
warning lights and the message "brake failure" on the instrument
panel with no fault codes in the computer
NOTESSpecial notes:
Only address this customer complaint after a complete check with the diagnostic tool.
Problem with external supply to the computer:
The computer is intermittently without supply because of bad contacts in the electrical
supply circuit.
Refer to the interpretation of fault DF001 Computer supply.
ESP_V05_ALP15