One problem related to brake antilock wheel speed sensor has been reported for the 2003 GMC Sierra. The most recently reported issues are listed below.
The contact owns a 2003 GMC Sierra. While driving less than 10 mph in a busy parking lot, the contact depressed the brake pedal before completing a left turn and felt the brakes shaking. The brake pedal extended to the floor. He was able to maneuver the vehicle to safety and continued to apply the brakes. He allowed the vehicle to coast until it came to a complete stop. The dealer stated that the failure occurred due to corrosion of the brake lines. The manufacturer would not assist with the repairs due to the corrosion. The failure and current mileages were 87,974. Updated 12/17/08. The rear main seal was leaking oil. The wheel speed sensor was replaced, due to the abs light illuminating. Updated 12/18/08.