K 2500 Truck 4WD V8-379 6.2L DSL VIN C FI (1989)
ABS Light: Customer Interest
Brakes - Repeated RWAL Code 10 Conditions
GMC NUMBER:
89-5E-122
GROUP:
5E Anti-Lock Brakes
DATE:
December, 1989
CORPORATE
NUMBER:
965013
SUBJECT:
REPEAT REAR WHEEL ANTI-LOCK (RWAL) CODE 10
MODELS:
1988-89 C/K TRUCKS
Figure No. 1
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 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
