ABS - Noise Information

9223buick04

Bulletin:
91-5-5

Date:
March, '91

Ref. No.:
91-117-5

Corp. Ref. No.:
175001


SUBJECT:
INFORMATION CONCERNING ABS NOISE
SELF-TEST NORMAL AFTER AN IGNITION SWITCH CYCLE

MODELS AFFECTED:
1988 - 91 RIVIERA/REATTA
1989 - 91 REGAL
1991 - LESABRE, PARK AVENUE/PARK AVENUE ULTRA
1991 - SKYLARK


All antilock brake systems (ABS) will perform a self-test called Initialization during acceleration after each ignition switch cycle.

During this test, the modulator exercises the valves, solenoids and motor as the system monitors all inputs and outputs. This test is initiated at a relatively low speed so the ABS can be deactivated in the event there is an abnormal condition detected. Depending on the application, initialization occurs at different speeds, (usually 3 to 8 MPH) and will vary in intensity.

As it is possible to hear and feel the initialization cycle, some customers may comment about it. Initialization is a normal condition, therefore, repair should not be attempted.