Owners of 2010-2017 Buick Enclave vehicles may note a clunk/thump noise on acceleration once after each key cycle that might be mistaken as coming from the engine compartment or suspension.
The system solenoids and ABS pump motor are commanded on and off to verify proper operation and the EBCM verifies the ability to return the system to base braking in the event of a failure.
Owners of 2010-2017 Buick Enclave vehicles may note a clunk/thump noise on acceleration once after each key cycle that might be mistaken as coming from the engine compartment or suspension. The noise may actually be caused by the second phase power-up self-test of the ABS.
This self-test begins when the vehicle is driven at a speed greater than 9 mph and the EBCM has not detected any traction control/vehicle stability-related concerns.
This phase of the power-up self-test may be heard or felt by the driver. The system solenoids and ABS pump motor are commanded on and off to verify proper operation and the EBCM verifies the ability to return the system to base braking in the event of a failure. The EBCM isolates all of the wheels briefly closing the four isolation valves and occasionally the driver may detect this by experiencing a momentary hard pedal. In most situations, this ABS self-test noise should be considered normal.
If a particular vehicle exhibits a noise that is louder than a comparable vehicle, the brake lines should be inspected for contact with the vehicle underbody or lines touching each other. If any contact is present, the lines should be isolated to minimize the noise produced by the ABS self-test.
Information for Technical Service Bulletins comes from ProDemand, Mitchell 1's auto repair information software for domestic and import vehicles. Headquartered in San Diego, Mitchell 1 has provided quality repair information solutions to the automotive industry since 1918.
