VEHICLES AFFECTED: 1992 "C" MODELS -------------------
Some 1992 DeVilles and Fleetwoods may experience a buzz noise from the Pressure Modulator Valve (PMV) during traction control operation. This noise is normal and not indicative of any malfunction. Traction control operation is addressed on pages 184-185 of the Owner's Manual and on a driver-side Sun Visor card.
The PMV pump operates during traction control to build pressure to the front brakes. The buzz noise is the sound of this pump operation being translated via the PMV mounting.
A Pressure Modulator Valve mounting bracket equipped with rubber isolators will soon be in production and available for servicing complaint vehicles and will be accompanied by an additional Service bulletin.
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.