RWAL SYSTEM CODE 7 DAIG./INFO. PROCEDURE FOR CLEARING CODES

Subject: REAR WHEEL ANTI-LOCK BRAKE (RWAL) CODE 7

Model and Year: 1988-91 ALL LIGHT DUTY TRUCKS WITH RWAL

After a repair has been made to the RWAL system on light duty trucks, technicians will need to clear codes and check for reoccurrence in order to verify the repair. To clear the stored codes, technicians must turn the ignition to the OFF position and remove the ECU memory power fuse (Stop / Hazard fuse on C/K and R/V trucks, Horn / Dome fuse on M series vans, Tail LPS fuse on G Vans, and ECM B fuse on S/T trucks). If the ignition switch is not turned to the OFF position, the ECU could be permanently damaged and a code 7 may be set. If this occurs it will not be possible to clear the code and the ECU will have to be replaced.

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.