Accelerator Pedal problems of the 2020 Cadillac XT5

The contact called on behalf of her grandmother who owns a 2020 Cadillac Xt5. The contact stated while driving approximately 60 mph and attempting to accelerate, the vehicle failed to accelerate while attempting to switch lanes. The contact stated that while depressing the brake pedal, the vehicle was revving; however, the vehicle failed to slow down as needed. The contact stated that the vehicle continued to accelerate to approximately 80 mph. The contact depressed the brake pedal for an excessive amount of time to significantly reduce the speed of the vehicle. The contact stated that the vehicle decelerated to approximately 70 mph. The contact became aware that the cruise control had activated independently. While attempting to deactivate the cruise control, the cruise control failed to deactivate. The contact pressed the start/stop button to turn off the vehicle. The contact pressed the button again immediately turning the vehicle back on and shifting into neutral, significantly reducing the rpm. The contact coasted to the side of the road and turned off the vehicle. After waiting for a while the contact turned the vehicle back on and continued driving. There were no warning lights illuminated. The vehicle was taken to the dealer; however, the dealer was unable to determine the cause of the failure. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was unknown.