2020 GMC Sierra 1500: headlights failing or too dim

Filed Aug 4, 2025 · Electrical, Engine · 250 miles · OR

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving with cruise control mode set at 55 MPH, the vehicle independently accelerated to 98 MPH, and then the vehicle lost motive power. Additionally, the contact stated that the vehicle had failed to turn off upon pressing the Engine Start/Stop button. No warning light was illuminated. The vehicle was able to restart and was taken to a local dealer to be diagnosed, but the cause of the failure could not be determined. Additionally, the contact noticed that water was leaking inside the vehicle through the rear window on rainy days. The contact stated that the infotainment screen had failed to turn on as intended on some occasions, and the screen had displayed a rearview camera image while the vehicle was in drive(D) on other occasions. The contact stated that while driving at various speeds, the transmission made an abnormal sound, and the RPMs failed to decrease as intended, but suddenly dropped while decelerating. Additionally, the contact stated that the headlights, the fuel pump, and the main pulley were replaced at the local dealer. The vehicle was not repaired. The manufacturer was notified of the failure and referred the contact to the federal safety agency Hotline for assistance. The failure mileage was approximately 250.

Filed Nov 9, 2022 · AZ

Once vehicle is put in park, the control panel comes and reads, “shift in park and radio and head lights stays on as well”. I exit the vehicle and it continues to display the mention above. I’ve restarted the vehicle and put it back in park still the “shift in park”, stays on. I exit the vehicle and monitored the vehicle for approximately 5 minutes and finally turned off. This never happened before, I’m afraid it may stay on one of these days and run the battery down.

Filed Sep 26, 2021 · Suspension · MN

The leaf springs appear to have failed. The vehicle is available for inspection. If the leaf spring brakes, control of the vehicle could quickly become an issue. On 9/24/21 I brought my truck into the local GMC dealer for inspection. The service technician indicated the leaf springs show “possible overloading” and recommended air bags to level the truck. The heaviest load for this truck has been a 4,000 lb. fiberglass fishing boat. At this time, no one else has inspected the truck. The truck, when empty, sits lower in the rear than in the front. If a small trailer is attached, it becomes even worse. Oncoming cars flash their headlights thinking mine are on high beam, which they are not.

Filed Feb 10, 2020 · Electrical, Lights · 144 miles · AZ

Brand new truck. Stuck at the gym in the middle of the night truck wont start. The interior lights, head lights, and radio wont shut off. Vehicle wont start. I'm assuming the battery was drained because interior lights, exterior lights, radio, wont shut off. Has to be some kind of electrical malfunction. Waiting on gm roadside.

Filed Dec 15, 2019 · Lights · 1,500 miles · IN

When making right turns in the dark the headlights do not cast light to the right so you can see where you are turning. This is especially a problem in the rural without streetlights it is totally black from the drivers seat looking over the right side of the hood or out the right window.