2020 GMC Sierra 1500 driver assistance problems

Filed Aug 24, 2026 · Driver assistance, Engine · GA · crash

Piston 5 dropped compression to 120 the rest were 190-200. The engine failed therefore none of my parking assist sensors were working and I backed into a car because the truck was misfiring.

Filed Feb 20, 2026 · Brakes, Driver assistance · NV

The brakes suddenly activate and cause the vehicle to rapidly stop with no warning of any kind and without any braking action being taken by the driver. Then, the brakes do not release and the vehicle cannot be moved as the brakes remain on. Turning the engine off and then restarting it or shifting to other gears does not release the brakes. The vehicle remains immobile and cannot be driven. After a few hours have passed, like overnight, the brakes release and the vehicle can started and driven just as if nothing had happened. A message briefly appears on the vehicle information screen each time this inadvertent braking occurs. It reads, “Brake Failure System”. These brake lockdowns occurred when driving on streets and in the driveway. No accident resulted but could have easily occurred. This is dangerous for a driver and occupants of a vehicle with this safety flaw as well as for other people and vehicles in the vicinity. This has happened five times. The last two instances resulted in the vehicle being loaded onto a tow truck and taken to a dealer of the vehicle’s manufacture. Thus far the dealership has not found what may be causing this intermittent braking problem.

Filed Oct 1, 2025 · Brakes, Driver assistance · 93,000 miles · PA

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving at approximately 35-40 MPH and hauling a trailer in stop-and-go traffic, there was white smoke coming from the exhaust pipe, and the vehicle started losing power. The contact was able to pull over to the side of the road, where the Electronic Stability Control (ESC) and the check engine warning lights illuminated. The parking brake was engaging and disengaging independently. After turning off the vehicle and waiting for approximately 15-20 minutes, the vehicle was restarted, and the contact drove to the nearest independent mechanic. The mechanic diagnosed the vehicle and determined that the ignition coils needed to be replaced. The vehicle was repaired; however, it was determined that the repair had not resolved the failure. The mechanic then diagnosed the vehicle's cylinder #4 failure. The mechanic was in the process of determining whether the lifter or camshaft had failed. The mechanic determined that the engine might need to be replaced. The vehicle was not repaired. The manufacturer was informed of the failure. The failure mileage was approximately 93,000.

Filed Sep 5, 2025 · Brakes, Driver assistance · 65,000 miles · NY

The contact owns a 2020 GMC Sierra 1500. The contact stated that on several occasions while the vehicle was started, the check engine, brake system, and another unknown warning light illuminated. Additionally, the messages brake system failure, steering wheel failure, low oil, and two other unknown messages were displayed. The contact also stated that the rear-view camera remained displayed while shifted into drive, and the instrument panel failed to operate as intended. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 65,000.

Filed Jul 19, 2025 · Driver assistance, Engine · MA

My GMC had a terminal engine failure around 5/3/25. This disengaged the ESC, parking brake, and driver assist abilities as well as making the truck undrivable. GMC service diagnosed the truck needed an entire new engine. The repair took over 2 months to complete and now that I have the truck back, the adaptive cruise control is not working.

Filed Jul 12, 2025 · Driver assistance · CA

1. Lane Keeping Assistantance: The green vehicle indicator on the dashboard will disappear and stay off while driving. When it is off, it is unsafe. 2. Parking Collision Warning: The front and back sensors will disappear and become nonfunctional while driving and parking. Sometimes they activate for no reason as well. 3. Both exterior mirrors: After starting the engine to drive off , both exterior mirrors will lower automatically from my setting. After the truck is started and driven off, they must be rest again.

Filed Apr 23, 2025 · Driver assistance, Electrical · 125,000 miles · NJ

The contact owns a 2020 GMC Sierra 1500. The contact stated while driving 40 MPH, the vehicle failed to properly respond. There were no warning lights illuminated; however, the message ESC was displayed. The contact stated that the brakes, steering, and a message to check the trailer brakes was also displayed. The contact pulled over to the side of the road and the brake pedal was depressed several times however, the brakes failed to respond, and the vehicle was difficult to control. The vehicle was towed by AAA and then towed to a dealer however, the vehicle was not yet diagnosed. The contact stated that the brakes were inoperable, and the control center was destabilized. The vehicle was not yet repaired. The manufacturer was made aware of the failure and referred the contact to the federal safety agency Hotline. The failure mileage was approximately 125,000.

Filed Apr 1, 2025 · Brakes, Driver assistance · TX

recently when starting truck brake message alert comes across on dash reading brake error, and not to drive above 45 miles per hour and brakes are NOT totally operational, meaning brake pedal has alot of play in it to bring truck to a stop. Have to turn off vehicle , sometimes repeatedly before it apparently resets computer system. This has now occurred four times in last five months. Events and dash warning message very similar to recall issued 3/3/20, but listed as "complete" on recall data base. Need to seriously and immediately looked into and corrected!

Filed Feb 12, 2025 · Driver assistance, Engine · 87,000 miles · OR

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving 65 MPH, the check engine and the traction control warning lights illuminated. The contact stated that a dealer was contacted. The vehicle was taken to a dealer where it was diagnosed and determined that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure and informed the contact that he would receive a callback. The approximate failure mileage was 87,000.

Filed Feb 3, 2025 · Driver assistance, Engine · TX

I have had no issues with my vehicle since I purchased it in July 2022 and keep up with the routine maintenance on it. About 2.5 weeks ago I was driving to work like I normally do and the truck started making a knocking noise and all these sensors lights came on the dash. The alerts were saying to service the parking brake, service ESC, and that steering assist is reduced and to drive with care. The vehicle also started shaking and would not accelerate properly or shift gears. We ended up taking it to the closest GMC dealership and they were in able to diagnose it just by simply hooking it up, they had to fully dismantle the engine in order to diagnose it. They came back and said cylinder number 4 is damaged as well as the lifters and cam shaft. I am no car expert but it is weird that a car that is relatively new and has the maintenance kept up on it should not experience a serious malfunction like this. What is even weirder is my sister in law has a 2020 Chevy Silverado where the almost identical thing just happened to theirs and it too is now in the show as well needing its engine and stuff repaired.