ORDERING THE CORRECT 4WAL BRAKE PRESSURE MODULATOR VALVE

SUBJECT: ORDERING THE CORRECT 4WAL BRAKE PRESSURE MODULATOR VALVE FOR 3-WHEEL OR 4-WHEEL SPEED SENSOR SYSTEMS

MODEL/YEARS: 1991-93 BRAVADA

SUBJECT: ORDERING THE CORRECT 4WAL BRAKE PRESSURE MODULATOR VALVE FOR 3-WHEEL SPEED SENSOR OR 4-WHEEL SPEED SENSOR SYSTEMS

Before ordering a replacement 4 wheel antilock (4WAL) brake pressure modulator valve (BPMV - formerly EHCU), BE SURE TO CONFIRM whether or not the vehicle is a 3-wheel speed sensor or a 4-wheel speed sensor system. This can be easily verified by looking under the rear of the vehicle for the sensor wires coming out of the rear wheel area. If the speed sensor wires are not present, the vehicle has a 3-wheel speed sensor system. input for the rear wheels comes from the vehicle speed sensor located at the transfer case. If the speed sensor wires are present, the vehicle has a 4-wheel speed sensor system.

Note: Most 1993 Bravadas have the 3-wheel speed sensors.

The 4WAL BPMV can be verified for proper application by reading the numbers under the bar code on the permanent bar code label (large white label on the top of the BPMV). Reading from left to right, positions 3 through 6 (total of four digits) correspond to the last four digits of the GMSPO service part number of the BPMV.

When a replacement 4WAL BPMV has been received, check the 4-digit number on the bar code label against the part number on the box to make sure you received the correct BPMV.

Note: If the 4WAL BPMV part number does not match the box it was delivered in, contact Service Parts Assistance Center (SPAC) immediately.

3-wheel speed sensor 4WAL BPMV'S, delivered for service fixes from GMSPO after February 1, 1993, will have an additional sticker attached stating "93 ONLY". A temporary label will also be located on the connector side of the module, stating "3 S" to identify a 3-wheel speed sensor 4WAL BPMV. A 4-wheel speed sensor 4WAL BPMV will not have the "93 ONLY" or the "3 S" stickers attached.

Important: If you have a problem identifying the proper BPMV part number for a particular vehicle, including whether the vehicle has 3-wheel or 4-wheel speed sensors, contact SPAC.

IMPORTANT SERVICE NOTICE:

A service replacement 4WAL BPMV will only operate correctly if installed into the correct wheel speed sensor application. If a replacement 4WAL BPMV is installed and codes 31 or 35 are set, this indicates the wrong BPMV was installed into the vehicle. Check to see if the vehicle has either 3-wheel speed sensors or 4-wheel speed sensors, and install the correct replacement 4WAL BPMV designed for that specific 3-wheel speed sensor or 4-wheel speed sensor application.

o IF A 3-WHEEL SPEED SENSOR BPMV IS INSTALLED INTO A 4-WHEEL SPEED SENSOR VEHICLE, THE ABS LIGHT WILL ILLUMINATE AND A CODE 35 WILL BE SET.

o IF A 4-WHEEL SPEED SENSOR BPMV IS INSTALLED INTO A 3-WHEEL SPEED SENSOR VEHICLE, THE ABS LIGHT WILL ILLUMINATE AND CODES 31,35 WILL BE SET.

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.