GMC Complaints

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.

The contact owns a 2019 GMC Acadia. The contact stated that after arriving at her destination and shifting into park(P), the message "Please Shift to Park" was displayed and the vehicle could be turned off. After several attempts, the vehicle returned to normal functionality, but the failure became a regular occurrence. No warning lights were illuminated. The vehicle was not taken to the dealer or an independent mechanic to be diagnosed or repaired. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the NHTSA Hotline for assistance. The failure mileage was 88,000.

The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign number: 24V797000 (POWER TRAIN), and the dealer performed an interim repair on the vehicle. In March 2025 the part was available, and the recall repair was completed. The contact stated that on one occasion, while driving at an undisclosed speed and then coming to a complete stop, the vehicle jerked and the transmission unexpectedly downshifted. The message “Low Power Mode” was displayed on the instrument panel. The vehicle then failed to accelerate as intended while depressing the accelerator pedal. The contact drove to a parking lot and turned off the vehicle. The vehicle was towed to Don Moore Chevrolet GMC, where it was diagnosed with transmission control valve failure. The contact was informed it would be months before the repair could be performed. The vehicle was towed to another dealer, where the transmission control valve failure was confirmed, and the contact was informed there were metal shavings found inside the transmission. The vehicle remained at the dealer unrepaired. The manufacturer was made aware of the failure. The failure mileage was approximately 115,000.

While driving on the interstate, I felt the engine "slip". Immediately afterwards, I heard a load knocking noise from under the hood, the check engine light came on, and the vehicle lost power. I was able to pull off the interstate. Called a towing company and got the vehicle towed to a GMC dealer. The dealership diagnosed the vehicle and noted a critical issue with the engine and transmission. Dealership recommends engine replacement. Vehicle is less than a year old with 15,400 miles on the odometer. This particular vehicle is not impacted by the GMC recall on their engine, however is has the same engine failure.

The contact owns a 2019 GMC Sierra 1500. The contact stated that the vehicle was taken to the dealer for an oil change service. The contact stated that while in the process of picking up the vehicle, the dealer informed the contact that the vehicle had failed to start. The dealer determined that the engine needed to be replaced and provided an estimate for the repair. The vehicle was not repaired due to the cost. The manufacturer was not notified of the failure and informed the contact that the VIN was not included in a recall. The contact was referred to the NHTSA Hotline for assistance. The contact related the failure to NHTSA Action Number: PE25001(Engine, Engine and Engine Cooling). The failure mileage was approximately 115,000.

As I was turning left from a county road to a highway my truck died on me. I was able to push it out of the road with the help of two other motorist. This is the second time in 4 months were my truck broke down due to engine failure. I had the motor repaired the first week in June 2025 for a similar instance. My truck is at the dealership right now awaiting repair because GM will not recognize that my 2019 6.2 L87 engine has the same known defects as other 2019 6.2 L87. This is a safety issue which GM refuses to acknowledge on my vehicle.

The contact owns a 2014 GMC Sierra 1500. The contact stated that while driving approximately 45 MPH, the vehicle drove over a slight bump in the road. The contact stated that the vehicle bounced, and then there was an abnormal banging sound coming from the rear of the vehicle. The contact recently had work completed on the exhaust system. The contact took the vehicle back to the independent mechanic who had performed the exhaust repair. The mechanic raised the vehicle on the lift and became aware that the rear passenger’s and driver's side cross members, supports for the shock absorbers, and the rear sub frame had extensive corrosion. The contact was advised by the mechanic that the banging sound was coming from the shock absorbers striking the bed of the truck while driving over the bump in the roadway. The vehicle was not repaired. The manufacturer was not informed of the failure. The failure mileage was 78,569.

The contact owns a 2013 GMC Sierra 3500. The contact stated that while driving at 50 MPH, the ABS independently engaged. A dealer was contacted. The vehicle was taken to the dealer to be diagnosed; however, the diagnostic result was unknown. The vehicle was not repaired. The manufacturer was not notified of the failure, and informed the contact that the VIN was not under recall. The approximate failure mileage was 14,000.

The contact owns a 2024 GMC Sierra 1500. The contact stated that while driving approximately 65 MPH, the vehicle rolled over a bump in the highway, and the message to "Slow Down" was displayed on the instrument cluster. The contact heard an abnormal metal-on-metal sound coming from the vehicle. The contact had taken the vehicle to a local dealer who diagnosed the vehicle and determined that the supports for the differential and the rear axles had been improperly attached and had become loose. The contact had asked the dealer if the repair could be covered under warranty, and was advised that the repairs were not covered. The vehicle was not repaired. The manufacturer was not informed of the failure. The failure mileage was approximately 48,000.

2022 GMC Sierra has a P1098 code. This code has to do with a faulty coolant control valve. This causes the engine fan to run constantly and displays on the screen "Reduced Acceleration, Drive with Caution". The truck does not have any power when this happens, which is 99% of the time. This makes using the truck very difficult in high traffic areas and pulling a loaded trailer. Apparently GM knows about this and is not getting the part to correct the problem to the dealerships in a timely manner. My truck was diagnosed with this problem over 2 weeks ago and still waiting on the part.