While traveling on a freeway, disengaged speed control using brake, but did not originally turn it off to be able to maneuver better in traffic near a city. Vehicle originally slowed down, but after releasing brake in 3 seconds, car sped up on its own with an acceleration profile greater than the one when you are setting the speed. Tried several times to get it to quit with this behavior and finally hit the cancel and off button on the steering wheel. All cruise control lights on the dash were off and no check engine warnings were on. This did not help the situation. When brake was on, vehicle quit acceleration, so with brake on, pulled on to shoulder and placed vehicle in park and immediately shut the engine off with key in full off position. Waited 20 seconds and restarted car and made way back to freeway. Did not use speed control anymore for the remainder of the trip. At the time the odometer was showing about 19150 actual miles. Made appt with Nissan dealer and took it in. On way to dealer, I pushed accelerator half-way to the floor to speed up quickly and the accelerator slammed its way to the floor. I applied brake and vehicle quit accelerating. I did not quit braking until vehicle was below 40. Vehicle did not accelerate again wildly the rest of the 30 mile trip to the dealer and I did not push the peddle very hard the rest of the way. Keep in mind the cruise control switches were not pushed at all during this incident and none of the cruise control lights were lit on the dash; the check engine light was not on either. The dealer was not able to find anything wrong with the vehicle and said they should replace the cruise control switch assembly on the dash. I personally consider this a very dangerous failure mode.

- Hartsville, SC, USA