2020 GMC Sierra 2500 FORWARD COLLISION AVOIDANCE

The contact owns a 2020 GMC Sierra 2500. The contact stated while driving 60 MPH, the vehicle independently slowed and dramatically decelerated. The vehicle returned to normal functionality, but the failure became a regular occurrence. The contact stated that when the failure occurred, the gear shifter position indicator light flashed, and once the vehicle returned to normal functionality, the light remained solid. No warning lights were illuminated. The vehicle was taken to the dealer, who diagnosed a failure with the Forward Collision Avoidance warning sensor. The vehicle was repaired, but the failure reoccurred. The manufacturer was not notified of the failure. The failure mileage was 102,000.

Was driving truck down driveway at about 5km per hour and the parking brake automatically engage bringing the vehicle to a sudden and unexpected hard stop. Brought to dealership, then said they cannot duplicate the problem and therefore there is no action to be taken.