ABS - Brake Pedal Pulsation At Low Speeds

91cadillac06

Bulletin No.: T-91-97
File in Group: 5E
Number 5
Corp. Ref. No.: 105002R
Date: June, 1991


SUBJECT:
ABS BRAKE PEDAL PULSATION WHEN APPLYING BRAKES AT LOW SPEEDS
(NEW WHEEL SPEED SENSOR)


MODELS AFFECTED:
1991 DE VILLES AND FLEETWOODS


Some 1991 DeVilles and Fleetwoods built before breakpoint M4288333 may experience unwarranted ABS brake pedal pulsation math normal braking below 10 mph. This condition may be caused by moisture intrusion into the rear wheel speed sensor, creating a false speed input to the EBCM.

The pedal pulsation due to moisture intrusion may or may not cause a trouble code to set. Install a Tech 1 scan tool to read any trouble codes that are stored, and follow the diagnosis charts in the Service Information Manual. Use the WSS speed display to observe erratic MFSS input.

If no trouble codes are stored or erratic WSS input is observed, replace both rear wheel speed sensors. A new wheel speed sensor, P/N 10456499 (one per box), has been released for service.

Parts are currently available from GMSPO.