One mile into commute, the accelerator pedal didn't respond after stopping, then suddenly responded causing car to accelerate rapidly. Repeated twice before the check engine light came on. Stopped car, shut the car off, checked gas cap was fastened securely. Restarted car. The check engine light remained illuminated. Turned around and proceeded the one mile home. Coasted into the parking garage and stopped the car to wait for the garage door to close. While completely stopped the car tried to accelerate without any input to the gas pedal. The RPM's increased and the car tried to drive forward. The RPM's didn't decrease until the car was placed in neutral. The sudden RPM increase while stopped caused the tires to squeal against the smooth pavement in the parking garage. Shut the car off, placed in park, restarted the car and pulled into my parking spot. The next day started the car and the check engine light was still illuminated. Drove the car approximately 5 miles to the dealer without incident. Dealer initially refused to provide a copy of the order and after insisting on having a copy the service manager neglected to indicate on the work order that the car suddenly accelerated without input to the accelerator pedal. Dealer refused to cover the cost of replacing the accelerator pedal position sensor under warranty and argued that the sudden acceleration without input or random increased RPM violates the 8/80K epa warranty or modern safety standards. Contacted GM warranty who also refused to cover the replacement cost under epa or safety warranty.

- Columbia Heights, MN, USA