BUZZ NOISE IS NORMAL DURING TRACTION CONTROL ACTIVATION

Subject: LOUD BUZZING NOISE DURING TRACTION CONTROL ACTIVATION (NEW ISOLATED ABS PRESSURE MODULATOR VALVE)

Models Affected: 1992 BONNEVILLE MODELS --------

CONDITION:

--------- Some early 1992 Bonneville models may experience a loud buzzing noise coming from the ABS pressure modulator valve during traction control operation.

CAUSE:

----- This may be caused by a non-isolated mounted bracket transmitting noise to the body of the vehicle.

CORRECTION:

---------- A new isolated ABS Pressure Modulator Valve Bracket has been released for service. Bracket Assembly No. 25607777 and Bolts Part No. 25607193 (3 req'd) are currently available from GMSPO.

SERVICE PROCEDURE:

1. Unbolt the pressure modulator valve bracket from the motor compartment side rail.

2. Remove the original bracket by unfastening the three attaching bolts.

3. Assemble the new bracket to the pressure modulator valve using the new shoulder bolts, part number 25607193. Tighten bolts to 9-10 N.m.

4. Attach the bracket assembly to the lower motor compartment rail and torque to 27 N.m (20 lb.ft.).

Parts are currently available from GMSPO.

WARRANTY INFORMATION:

Labor Operation No.: T5267 Labor Time : .6 hr.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.