GMC Complaints

Driving on highway, engine stopped while driving 70+ mph. Had to get to the side of the multilane highway. Was towed to nearest GMC dealership. Dealer said the engine was locked up, and they have many vehicles right now with similar problems. They will have to replace the engine due to complete engine failure.

I brought my truck into a certified GM dealer for recall work on the ground strap. I left the dealership and multiple lights came on dash: check engine light, service ecs, traction control, service parking brake, steering assist reduced. 7 minutes later the engine began miss firing. The dealer asked me to bring it back to the shop and after some digging they discovered my L87, 6.2 engine was missing firing in cylinder 5. Now the motor needs to be replaced and GM is not standing behind the repair.

The contact owns a 2019 GMC Acadia. The contact stated that while driving at an undisclosed speed, the transmission failed to properly shift gears and the vehicle failed to exceed 40 MPH while driving. The contact stated that the transmission failed to shift above third gear. The check engine warning light was illuminated. The vehicle was taken to an independent mechanic, who discovered that there was no transmission fluid inside the torque converter. The vehicle was scanned and displayed an issue with the transmission control module. The local dealer was contacted and confirmed that the VIN was not included in NHTSA Campaign Number: 20V668000 (Power Train). The vehicle was not diagnosed or repaired. The manufacturer was contacted and referred the contact to the NHTSA Hotline to report the failure. The approximate failure mileage was 154,429.

shifter micro-switch is not working and is available for inspection upon request. Vehicle is not shutting off as it is indicating shift to park. The vehicle unable to shut off can cause issues while parked in the garage still running and worried about causing a fire. Problem diagnosed by private individual but have plans on taking it to dealership. The shift to park indicator issue has been occurring for almost a year and has progressively gotten worse. I have noticed other vehicles with the same make/model/year have had similar issues with known defects that a recall was issued.

Complete failure on Cylinder 3 after AFM system caused lifter collapse in 5.3L V8. Lifter fell into cam shaft and scored the shaft at 55mph. Truck started surging and shaking violently. Truck shaking had me swerve to the side of the road as I was coming up on a crosswalk with golf cart about to cross the road. Vehicle was inspected at Atwater GM in Aitkin, MN and component failure was identified. Two weeks later I paid $14,149 to have a complete engine replacement. There was absolutely no indication that this event would take place. Just months before I took this truck from [XXX] to [XXX] and back without an issue. GM should be held responsible for a complete lack of safety due to faulty AFM engines. Not only did this endanger my safety, but I also had to withdraw from my 401k to pay for the outrageous cost of a new engine replacement because of a single point of failure. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

My truck was serviced for the front chrome grill separation recall last year. On Saturday, 8/1/2026 while driving at highway speed the grill deflector separated from the vehicle violently. I was able to pull off of the highway and remove the part as only the passenger corner clip (with screw) was partially retaining the deflector. Upon looking at the "repair" or recall, the corrective action does not appear to have been done correctly per N242490120. The chrome coating was not scuffed let alone removed from the part and an insufficient amount of epoxy was used to attach this deflector. Damage was done to the hood and lower grill during this incident. I have had numerous and considerable issues with the purchasing/servicing dealership where I bought this truck.

I got into my car to run some errands. As I drove away from my house, I made a left turn downhill. I noticed vehicles ahead, so I began to slow down. At that moment, I was driving between 20 and 25 mph. When I tried to brake, my brakes failed and started flashing a brake failure warning light. I kept pumping the brake pedal, and eventually, the car slowed down and came to a stop. I turned on my hazard lights, and immediately returned home. My nephew and I were both in the car. Our live flashed in front of us. Thankfully, there were no vehicles directly in front of me or pedestrians. This could have turned out to be the worst day of my life if anyone had been injured.

No incident but steering assisted reduced could cause an issue. Also the fix is to reset the computer by detaching the negative pole on the battery. This could be an issue due to the heat in the car someone could get burned.

While driving on XXX I received a message on the dash: service transmission, will not be able to shift soon. I went to the nearest GMC service center, located in [XXX]. Their diagnostics indicated that the Gear Shift Control Module needed to be replaced with new PN 86421783. That part was not available until XXX, but old PN 86274946 was available at a few dealersships, and it acould possibly be ordered and arrive sooner than XXX. I was told that driving the truck would be okay, but the part should be replaced as soon as possible. I live over an hour's drive from [XXX], and with the assurance that driving the GMC was okay, I chose to have the part shipped to and replaced at the dealership in [XXX], the nearest one to [XXX]. I drove back to [XXX], stopping at the Waldoboro dealership to make an appointment for their inspection of my truck, their troubleshooting the problem, and ordering the necessary parts to repair the transmission. When the part number went into their ordering system, the dealership was advised that no parts were available and no availability date was known. I contacted GMC Customer Assistance to express my concern and request assistance in locating the parts, but she was also unable to locate the parts or speed their availability. Again, on the assurance that the truck was okay to drive, on XXX I drove to my storage units near [XXX], and when I tried to leave and shifted into reverse the truck would not move. AAA towed me to the dealership in Waldoboro, and the replacement parts search began. Finally, on 7/28/26 I was advised that the part was at the dealership, and on XXX I picked up my repaired GMC truck. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Vehicle shudders at acceleration at times making merging onto highways and passing vehicles dangerous.