One problem related to steering anti-theft device has been reported for the 2003 GMC Sierra. The most recently reported issues are listed below.
The contact owns a 2003 GMC Sierra 2500 hd/diesel. The contact complained about a steering problem. . The steering vibrated when making lower speed turns. This happened when moving or sitting still. It has been fixed approximately 4 times, and it recurred after about 3,000 miles. At 10,000 miles when applying the brakes the steering locked. Also, when applying the brakes the contact lost the brake pedal, it got soft and spongy. They did not pulsate. Also, this affected the steering, the vibration in the steering, and the brakes, which were separate issues. The dealer could not duplicate the problem. He said there was a service bulletin concerning this issue, but the contact's vehicle VIN was not included.