1. while traveling on an interstate highway, the vehicle's "stabilitrak" control abruptly shut down, and the brakes locked with light depressions of the pedal. (stabilitrak controls the vehicle's traction control, anti-lock brakes, and roll-prevention program.) 2. the failure has occurred approximately 5 times; on one occasion, the engine stalled in addition to the above. Consequences were as described above. 3. the vehicle was taken on an urgent basis to the GMC dealer the following day. The dealer advised that the problem is due to "play in the camshaft, " which sends an erroneous signal to the stabilitrak, causing it to shut down. The dealer advised that repair will require replacement of cylinder heads and other equipment, which is a draconian procedure which will take a week or more. In addition, the dealer advised that the problem is causing permanently damage to the vehicle's drivetrain which worsens with miles driven. The dealer further advised that repair parts would not be available for at least 8 weeks because the problem is widespread in the vehicle line and GM refuses to manufacture parts in sufficient quantities to meet the national demand. Almost 8 weeks after reporting the problem, the problem remains unrepaired, and GM has refused one written request and one written demand for immediate correction of the problem, despite this being an immediate threat to occupant safety in that it shuts down the vehicle's most important electronic safety components, including traction control, anti-lock brakes, and the anti-roll-over program.

- Falls Church, VA, USA