Two problems related to steering anti-theft device have been reported for the 2004 GMC Sierra. The most recently reported issues are listed below.
Quadra steering locks up, causing the rear of the truck to veer to the left and the entire truck to travel in a crabbing or angled position. On two lane road the rear is in the oncoming lane and the vehicle is nearly impossible to control. Message on dash is "service 4 wheel steer" dealer can not find a problem. Vehicle still at dealership.
Consumer complained about a steering problem. The steering locked up. Took vehicle to the dealer, and also contacted the manufacturer. Consumer was told that the manufacturer was aware of the defect. However, the service technician at the dealer did not know how to repair the problem.