GMC Complaints

Traveling on the interstate at highway speeds of 75mph and the engine spun a bearing resulting in complete engine failure.

Engine failure. Lifters failed causing internal engine damage. No previous warning. 160000 miles. Repair cost is $5000

My transmission does not engage properly. From a starting position when I step on the gas the transmission lags and when it catches it slams / bangs into gear

I leased this vehicle on May 17, 2024, expecting it to function as intended. Instead, within months, it suffered recurring and escalating failures that have rendered it unsafe and unusable. January 7, 2025, I brought the truck to Gates GMC for routine service and reported that it had lunged forward by approximately 2 to 2.5 feet while shifting into park. Additionally, it exhibited irregular acceleration and rough down shifting in lower gears. I also communicated the check engine light has come on and gone off on the dashboard over the past week a few times without receiving any information on the app. At this January 7th visit, GM performed Recall N242435631, supposedly addressing a known battery drain defect that caused total vehicle shutdowns. On January 24, 2025, I started the truck and was immediately overwhelmed by an intense chemical odor coming through the ventilation system. January 31 – February 1, 2025 – Erratic Engine Warning Lights & Diagnostic Failures On January 31, 2025, at 5:28 PM, on this key cycle the check engine light illuminated but failed to register in the GM app. On the next key cycle, the warning disappeared. The following morning, February 1, 2025, at 10:26 AM, the check engine light Appeared on the first key cycle before disappearing on the second key cycle. The onboard diagnostics system failed to log or retain these warnings. On February 7, 2025, the vehicle suffered a complete electrical failure. no electronic function whatsoever. Roadside Assistance attempted to jump-start the truck using a high-powered jump pack, but it remained inoperable. A ford super duty and jump pack were needed to force start the truck. February 10, 2025 the truck suffered another total electrical failure and required towing to Gates GMC. The app indicated the Brake System, Anti-Lock Braking System, Emissions System (Specifically the exhaust system), and Power Train requiring service. My truck is at Gates GMC and was drawing 90 milliamps opposed to 40

Since my purchase of the vehicle Dec 2023, the tailgate opens on its own. Usually follows hitting a bump such as the rain gutter entering a store parking area. I have also had it occur while driving down the road. Have been told multiple times by my service personnel they have had same complaints from other Sierra 1500 but have no fix for the problem. They have offered to deactivate the electronic tailgate system but this is unacceptable to me. There is a recall for 2500 models with same issue but not for 1500’s. This makes little sense.

Took truck to dealership for transmission issues such as hard shifts and shuttering on highway. Waiting 2 months for parts that didn’t fix the issue. Now waiting on another transmission which I’m being told is on back order!

The systems have become unavailable. Took to dealership and they were told it just needed a software update. Dealer performed update GM sent and did not work. Dealer was told GM engineers would need to find a fix. I complained to GM and asked that they replace the cameras, especially because the vehicle is under warranty, and I was told no because that won't fix the issue. They don't even know what needs to be done to fix the issue though, but won't try a camera swap. They told me I need to take it back to the dealer so they can run diagnostics on it when the issue happens. I don't know what is so hard to understand that the issue is always there; the systems don't work and my dash always has the light the forward collision system not on and given a message when I start the truck that it is not available. This began to be an issue around 9000 miles. It first started by saying window camera blocked due to frost, but when it was clear, and I cleaned every camera and sensor, it still would not come on. This was 1.5 months ago. I don't understand why they are not trying to expedite fixing this safety issue. The dealer can't do anything until GM tells them to change out camera or send another fix, but there is no software fix available. I can forward emails between myself and GM and you can clearly see they are not listening. If that would be helpful, please let me know how to forward them.

7500 miles and transmission valve body failed. Parts are on back order with no eta.

Brakes stopped working while driving. Yes it has been reproduced by mechanic. No it has not been inspected by manufacturer. “Service Brake Assist” message populated after failure.

We were driving uphill on the highway, about 60 mph when the engine appeared to loose some power for about 10 seconds even though the engine was reving higher, and the ln the engine cut out. We coasted to a stop and then the electrical system was cutting out. I tried to restart the engine but it would not turn over at all, and the car’s electrical was intermittent. There was no warning or error lights before or during the engine failure. Photos provided are the messages on the instrument cluster when attempting to restart the engine. Vehicle was towed to the local GMC dealership, and they are replacing the engine under warranty. No eta on the engine replacement at this time.