GMC Complaints

the flexible steel cable connecting the seat belt to the seat separated and broke resulting in no way to use the seatbelt/connecting the seat belt to the connector on the seat.

These tires are not safe for off-road to highway use. After transitioning to the highway from a gravel driveway, I noticed that rocks were stuck in the treads. A significant about of rocks became dislodged and start to contact my vehicles underbody steps. I feel as if this can create significant and costly problems for the vehicles that are following close or perhaps behind in any manner. Large rocks and what I would classify as mini boulders are often found lodged in the tread and don't come out till they are picked out or fly out.

When I’m driving on the highway, I get a message on my dashboard saying steering assist reduced, drive with care. I have taken to the GMC dealership and they will not cover this repair even though it would be covered for 2021 GMC. When this happens, my car makes a loud noise and my steering wheel does not feel right. I do not feel safe.

On XXX, I was towing my camper to Copper Center, Alaska from Palmer, Alaska when my truck experienced a full transmission shut down which put the truck into "Reduced Power Mode". We descending down the road right next to Victory Bible Camp (64741 Victory Rd, Sutton-Alpine, Ak 99674) when the exhaust break turned off and the truck decreased power and the Check Engine Light illuminated. The Diagnostic that was produced by OnStar revealed 3 different codes. ( P0700 TCM, P0747 Pressure Control Solenoid A is stuck in the "ON" position, C116b faulty brake pad wear sensor.) I called GMC of Palmer and GMC OnStar advisor, both informed me that the truck needed to be towed. My safety concerns is this.... I had minimum cell phone signal and not a gas station or service station within MILES. I was on the side of the Alaska Highway 1 which is a major thoroughfare for traffic going to and from [XXX]. Thankfully there were a few kind folks that pulled over to offer assistance. My truck is a 2023 GMC Sierra 2500hd with only 26,262 Miles on it. I purchased this vehicle XXX. (It Still has the Temporary Tags on it.) If had been in a different part of Alaska when this transmission failed to function properly then we could be talking about a life or death situation. Especially, if my child was with me. I was hauling my camper that weighed ATMOST, 7,000 pounds. This is less than 40% of the trucks ability. I feel that this could put someone into a dire situation had they not had the experience with emergency situations like I have had. (Prior Military Service). I have also filed a complaint with GMC Motors. Case# XXX. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The Screen calls my own phone number and hangs up over and over if I just ended a call. I am not able to use any part of the screen afterwards such as my map. It stays like that until I disconnect the Bluetooth and wifi from my phone while trying to drive. Safety issue!

Steering assist reduced is the warning. The AC will no longer work and the fan runs constantly. From what I’ve read, it is a popular problem for Acadia owners and the thermostat and sensor has to be replaced. We have not been able to replace ours yet because of the cost.

When backing up, either on a hill or flat surface, the brakes fail to stop the vehicle. There is a pulsing sensation with the brakes due to failure of the vacuum. The brake pedal also becomes impossible to depress. No warning lights appear when this occurs.

I believe I had a lifter failure as I was traveling up SR 393. Safety issue as vehicle lost power. Vehicle is at dealership now and confirmed possible lifter collapse. No dashboard lights were on or any power issues prior.

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the "Add oil to engine" message was displayed. The vehicle was driven to an AutoZone within two minutes and turned off. Upon inspection of the engine oil level, the contact observed that the dipstick was completely dry. The dealer was notified of the issue, and an appointment was scheduled for an oil consumption test. The vehicle was not yet diagnosed or repaired. The contact stated that the vehicle had been serviced for a routine oil change on April 21, 2026, at 53,590 miles. The contact related the failure to NHTSA Action Number: RQ26001(ENGINE). The manufacturer was not made aware of the failure. The failure mileage was approximately 56,802.

I own a 2021 GMC Sierra AT4 3.0L Duramax (VIN [XXX]). The vehicle has codes P1098 (Coolant Control Valve Performance) and P129F which coincides with the first code. My dealer believes this is consistent with an Engine Coolant Control Valve failure. I understand Special Coverage XXX exists for this issue, but I've been told my VIN is not included. My truck has the exact engine, symptoms, and diagnostic codes addressed by Special Coverage N252508341, but my VIN is excluded. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)