2021 GMC Sierra 1500 driver assistance problems

Filed Jun 26, 2026 · Driver assistance, Electrical · MO

When I put the vehicle in park, the dash warning says it is not in park or shift to park. The components continue to work. I have taken it to the dealership and according to the service manger, this is a very common occurrence in these trucks. This seems to me that it would be a very serious safety issue if one assumes their vehicle is in park and it is actually not. The shift to park warning is a safety warning to alert the driver it is not in park so the vehicle doesn’t roll off and hit someone (especially a child playing in the driveway). Assuming that alert is just a malfunction could get someone killed. I did notice that this was considered a safety recall for some models of GMC vehicles but not others. I’m not sure why there hasn’t been a recall on these trucks when the service manager specifically said they are having this issue on a lot of trucks.

Filed May 30, 2026 · Driver assistance, Engine · FL

The truck randomly will not detect that it was shifted into park. Shifting between gears and back to park does not automatically fix the the issue and has taken up to 10 mins to turn the truck off. The adaptive cruise controls stopped working and can still use regular cruise control. Just not adaptive. It appears greyed out. The truck has thrown the error code: P1098, Engine Coolant Control Valve Position Sensor Minimum Stop Performance. The truck would go into limp mode until the error was cleared. This error has appeared 4 times over the past five months. The most recent date of it happening was today. 06/30/2026

Filed May 19, 2026 · Driver assistance, Electrical · IN

2021 GMC Sierra AT4, VIN [XXX] , the federal safety agency Campaign 25V‑274, GM Case XXX. Brake pad monitor failed at 128,923 miles -- 24 miles after leaving Penske Chevrolet (released at 128,899, RO XXX, 04/17/2026). Brakes became spongy immediately following service. Monitor disabled entirely to stop recurring red Service System alert. Root cause is a burnt fuse block ground fault confirmed in writing by two GM-authorized dealers. Ray Skillman (RO XXX, 06/05/2025) documented the fault then deleted Labor Operation 14BUZ ENGINE ELECTRICAL from the recall repair work order. Penske documented verbatim: "all of these other faults share this same ground circuit." The recall repair at Ray Skillman used a remanufactured short block instead of a complete engine per N252494002. The original seized-engine oil pan has never been replaced across three dealerships and 128,000 miles. GM's own Part 573 filing states this defect "increases the risk of a crash." I drove 300 miles on an interstate on 04/22/2026 with active brake warning and no loaner because GM Executive Resolution refused to authorize one. Three GM dealers have inspected this vehicle. GM Executive Resolution Team [XXX] ) has not returned calls or emails and has not confirmed in writing this vehicle is safe to operate. OnStar issued a Critical Alert for P0617 on 04/15/2026. Zero brake faults existed in the 13 months prior to the Penske visit. This is a direct continuation of unresolved electrical damage from a botched federal safety recall repair at 384 days and counting. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Feb 21, 2026 · Driver assistance, Engine · TX

I was driving on a highway on my way home from work. Thank god there was not a lot of traffic because my truck just shut off lost all power, then I received a message on the dash to put on neutral and restart. I tried multiple times to turn it back on. It never turned on and had to get it towed to nearest dealership. It took them a week to inform that the engine locked up even though I tried to take it for the recall they told me to wait and reschedule the appointment. Never got a new appointment until the engine failed and I got it towed to the dealership and have also not received a new kind of loaner from GM. This will be my last GMC truck I purchase.

Filed Jan 10, 2026 · Driver assistance · PA

The front camera stopped working, causing the safety systems to shut off. Codes U026A & U0078 "no communication failure". The camera was ordered and replaced.

Filed Dec 8, 2025 · Driver assistance · FL

Vehicle experiences a failure to the Lane Departure Warning and Intellibeam headlamps functions, primarily at night. Trouble first began on 3/12/2023 and has been to two GM dealerships for 11 repairs and the problem is still unresolved. GM Executive Escalations have been opened and the problem is still unresolved. Their response is that 18 vehicles experienced this problem and the resolution was to clean the front windshield and update the camera software. This truck has had the camera replaced and software updated three times by two different dealerships. GM is now stating they are unwilling to resolve the problem any further and they would no longer send any Field Engineers to investigate the problem. I have numerous photos, videos and repair logs from with the problem and resolutions performed. Nature of problem: At night, the indicator button for selecting the Lane Departure Warning will go out. If the button is depressed, a message in the DIC indicates Lane Departure Warning Unavailable and there is no way to activate the LDW. It also causes the Intellibeam headlamps to not work. Any help you can provide is greatly appreciated.

Filed Nov 18, 2025 · Driver assistance, Engine · LA

Engine burning oil and blowing white smoke out tail pipes. Have to add oil every 1500 miles or sooner if towing. Has been an issue since first oil change. Vehicle is now at 88057 miles

Filed Aug 5, 2025 · Driver assistance, Electrical · MO

2021 GMC Sierra 1500 [XXX] miles 36,500. My childs seatbelt does not work and the lane keep assist does not work INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed May 6, 2025 · Driver assistance, Engine · FL

El motor de mi camioneta falló por completo empezó a hacerle unos ruidos muy fuertes dentro del motor con solo 80,000 millas es del 2021 la compré el año pasado no llegó ni un año de uso una camioneta que supuestamente era muy buenas Estaba en el momento de lo sucedido estaba con mi mujer y mi hijo en el auto regresábamos de un restaurante acá en Miami y la camioneta se paró de pronto La camioneta fue inspeccionada por la garantía extendida la cual no asumió la reparación Luego del problema si salieron luces amarillas y rojas en la pantalla de mi camioneta

Filed May 30, 2024 · Driver assistance · SC

I am writing to complain about that General Motors has issued a retrofit program for 2022 model vehicles that did not come with safety features due to the microchip shortage. I purchased my vehicle new in 2021 and the vehicle did not have the option of having safety features at the time of purchase. I find not having the safety features in a large vehicle to be a safety concern for those that use the vehicle or around the vehicle. General Motors should add the 2021 model vehicles that also did not have the ability to have those features on them added as a part of their retrofit program.