2000 GMC Sierra cruise control problems

The consumer was at a stand still when putting the vehicle in reverse, the consumer pressed the accelerator pedal and there was some resistance in the accelerator pedal and then the pedal dropped straight to the floor. When the vehicle was moving backwards, the owner hit the brake and the vehicle began to accelerate on it s own at a high rate of speed. The consumer crossed two lanes of traffic and hit a guard rail. Provide further details.

Throttle becomes sticky when closed. As a result extra force is required on the accelerator when initialy depressed. This is an extremly dangerous situation especialy in parking lots or other tight, highly populated areas since extra force is required on the accelerator to "break it free" once it does "break free" the vehicle can lunge/lurch foreward uncontroled. This situation makes smooth throttle control unobtainable.