Speed Control Linkage problems of the 1998 GMC Sierra

While in reverse and going down a sloped driveway in winter condition, vehicle suddenly accelerated to an unknown speed. It crashed into a tree on other side of the road. Dealership has not examined vehicle. The truck was examined by dealer's service department. Technician cleaned linkage and made accelerator pedal easier to operate. The technician stated that a carbon build up on some related part when engine was cold, might have caused a malfunction.

While driving vehicle will lunge forward, and will not return to the rpm until about 5 seconds afterwards. Manufacturer stated that is the way the computer operates.