REPEAT REAR WHEEL ANTI-LOCK CODE 10 REVISED SWITCH/BRACKET

Subject: REPEAT REAR WHEEL ANTI-LOCK (RWAL) CODE 10

Model and Year: 1988-89 C, K TRUCKS

Some 1988 and 1989 C, K trucks may experience repeated RWAL Code 10 conditions. Code 10 may be set when the vehicle is travelling over 37 MPH and the RWAL module (ECU) sees an open circuit or no voltage at the stoplamp switch circuit. Regular service brakes and stoplamps continue to function normally, however, the stoplamps could stay on at times.

This condition has been corrected through the introduction of a revised stoplamp switch and cruise control release switch bracket into production. The VIN breakpoints are listed below. Internally the new stoplamp switch contains contact points which have been lengthened in order to allow more pedal travel before lighting the brake lamp. The new stoplamp switch can be identified externally by an additional rib that has been added to the side tab (see figure 1). The lower weld on the new cruise control release switch bracket has been moved .75 mm (1/32 inch) forward. The revised stoplamp switch and cruise control release switch bracket should be used ONLY in cases where brake switch adjustments have not corrected previous Code 10 conditions.

IMPORTANT: The stop lamp switch procedure does not change for the revised switch. The switch adjustment procedure is given in Service Bulletin 965001.

VIN Breakpoints

OSHAWA 2GCEK19KOK1205982

FT. WAYNE 1GCDK14K4KZ230782

PONTIAC 1GCDC14Z7KE229109

Parts Information

Part Number Description

15607063 Stoplamp Switch 15607068 Cruise Control Release Switch Bracket

Parts are currently available from GMSPO.

For repairs to vehicles under warranty use:

Labor Operation Number: T8035

Labor Time: 0.3 Hrs.

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.