Driving on the interstate without cruise control on at 70 mph. I had a vehicle passing in the fast lane and a vehicle in front of me slowing down so I applied a little pressure to my brake peddle and my truck automatically began to accelerate on its own. I kept pushing on the brake peddle and it was stuck in a acceleration. The brakes tried slowing it down but it would not stop acceleration once I took my foot of the brake peddle it just rapidly began to pick up speed on its own again! I ended up pushing down on the break peddle long enough to turn off the engine and coast off to the side on the interstate. I was so glad it happened while I was driving it and not my wife she could of wrecked into the back of the vehicle in front of us and caused a multiple car crash! The Electronic Throttle Control (ETC) light came on while I was pushing down on the brakes to try stopping the truck, but once I turned the engine off and back on again the (ETC) did not come back on although the brake lights stayed on for about 10 miles.