Exhaust System Emission Control Urea Injection System (def) problems of the 2020 GMC Sierra 1500

The contact owns a 2020 GMC Sierra 1500. The contact stated that while starting the vehicle, the engine hesitated while turning over. The vehicle started with the check engine warning light illuminated, and the def (diesel exhaust fluid) sensor light was illuminated. The message “94 miles before vehicle enters limp mode" was displayed and instructed the contact to see the diesel exhaust fluid section of the owner's manual. The vehicle was restricted to a 65 mph max speed. The vehicle was towed to a dealer, where it was diagnosed, and it was determined that the def tank pump assembly had failed and needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 121,000.

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving at 65 mph, the def tank failed. The vehicle went into three phases of limp mode and the vehicle unexpectedly decelerated while driving. The def system service message was displayed. The vehicle was taken to the local dealer, where it was diagnosed with def tank failure, and the tank needed to be replaced, even though the tank was full. The part was on backorder for several weeks. The contact was not provided with a loaner. The vehicle was repaired. The manufacturer was contacted and opened a case, but no additional assistance was provided. The failure mileage was approximately 70,000.