NHTSA Complaint #11689640 — 2021 CHEVROLET SILVERADO 1500

The contact owns a 2021 Chevrolet Silverado 1500. The contact stated that while driving at various speeds, the check engine warning light illuminated, and the transmission shifted independently to a lower gear. The contact stated that the downshift of the transmission caused the rear wheels to lock up. The contact pulled over and turned off and restarted the vehicle, and was able to reset the transmission. The contact stated that the failure was intermittent, but whenever the failure occurred, the check engine warning light was illuminated before the vehicle shifted to a lower gear. The vehicle was taken to an Auto Parts Store, where a handheld scanner was used to clear the transmission fault code. The contact stated that after the code was cleared, the vehicle operated normally, but the failure eventually reoccurred. The contact had not taken the vehicle to a dealer or an independent mechanic. The vehicle was not properly diagnosed or repaired. The contact researched online and related the failure to NHTSA Campaign Number: 24V797000 (Power Train); however, the VIN was not included in the recall. The manufacturer was not informed of the failure. The failure mileage was approximately 72,000.