ABS Light On, Front Wheel Speed Signal DTC
File In Section: 5 - BrakesBulletin No.: 66-50-09
Date: April, 1996
Subject:
ABS Light is Illuminated, Front Wheel Speed Signal DTC Stored
(Replace Front Brake Shield Assembly)
Models:
1993-95 Chevrolet and GMC G3 Van
with Brake RPOs JB7, JD7, JB8
Condition
Some owners may comment that the ABS light is on.
Cause
The front ABS wheel speed sensor wire may be pinched or cut when the steering is rotated full stop, left or right. A DTC referencing a wheel speed signal fault will be stored.
1993-95 Vans built prior to VIN Breakpoints: Chevrolet SF167199, and GMC SF526969, the front wheel speed sensor wire is attached to the upper control arm assembly with a single bracket assembly.
Vans built after the above VIN Breakpoints have a 2 piece bracket/clip design. During a full stop, left or right turn, the wheel speed sensor wire located at the bracket/clip, attached at the upper control arm assembly, may be caught between the steering knuckle and splash shield, pinching or cutting the wire.
Correction
Install a new front brake shield assembly and bend the bracket/clip upward/toward the upper control arm assembly. This will allow clearance between the upper control arm assembly, splash shield, and steering knuckle (reference Figure # 1). DO NOT bend bracket outward/away from the upper control arm assembly.
Notice:
The front wheel speed sensor wire is very sensitive to twists, kinks, crimps. If the wire becomes twisted, kinked, or crimped, the very fine wires may become damaged internally and may be unnoticed by visual inspection. DO NOT ATTEMPT TO REPAIR A FRONT WHEEL SPEED SENSOR WIRE.
Important:
Never remove existing clips from wires. Some wires come with bracket/clips installed onto the wire. If the wire clips are not installed, there are painted markings located on the wire for proper clip installation locations.
Service Procedure
1. Raise vehicle on hoist.
2. Inspect the wire at the upper control arm assembly bracket (Figure # 1, Item 1) /clip (Figure # 1, Item 2) for signs of damage. If pinched or cut, replace the front wheel speed sensor/splash shield assembly. Refer to the Service Manual Sections 5B and 5E.
3. Turn steering wheel or move wheels back and forth allowing travel from stop to stop. inspect the wire and verify clearance or any contact being made with the steering knuckle.
4. Inspect the wheel speed sensor wire bracket (Figure # 1, Item 1) /clip (Figure # 1, Item 2) for correct positioning. The clip tang (Item 2) should be oriented in the locating hole. As the wire is dressed, it should route toward the splash shield and steering knuckle. If not, remove the nut at the clip and rotate wire to obtain correct positioning. (Refer to Figure # 1.) The Nut torque requirement is 18 N.m (13 lb.ft).
5. Using a pair of channel locks or vise grips, bend sensor wire clip (Figure # 2, Item 2) under the upper control arm assembly until the bottom of the clip is level with the bottom of the upper control arm flange (Refer to Figure # 2, Item 2). Use care as to not damage or pinch the wire when bending clip. Turn the steering stop to stop and inspect for wire or clip contact to knuckle.
6. Road test and then re-inspect. The road test should include turning the steering fully in each direction.
^ Verity the clip did not contact the top of the knuckle.
^ Verify no wire contact with the knuckle.
Parts Information
Parts are currently available from GMSPO.
Warranty Information
For vehicles repaired under warranty, use as shown.
Important:
Labor operation is coded to base vehicle coverage in the warranty system.