GMC Complaints

The contact's wife owns a 2019 GMC Terrain. The contact stated while driving 70 MPH and depressing the brake pedal, the brake pedal was firm, and the vehicle failed to respond as needed. The check engine warning light was illuminated. The contact stated that upon depressing the brake pedal with excessive force, the vehicle responded as needed. The contact stated upon inspecting underneath the brake booster, the contact noticed a lot of debris due to lack of vacuum pressure. The dealer and the manufacturer were notified of the failure and referred the contact to the NHTSA Hotline to report the failure. The vehicle was not diagnosed or repaired. The failure mileage was approximately 80,000.

Subject: Urgent Safety Complaint Dear GMC Customer Service, I hope this message nds you well. I am formally reporting a serious safety issue with my GMC vehicle. The car has experienced multiple dangerous incidents due to likely electrical or software faults, losing power suddenly on two occasions while driving. This is especially concerning given the low mileage of 20,000 km and that the vehicle is still under warranty. Vehicle Information: • Model: GMC Sierra SLE, 2024 • VIN: [XXX] • Current Mileage: 20,000 km Description of the Problem & History: 1. First Incident (At 3,000 km): o The vehicle completely shut down due to an electrical or system software issue while driving. o The vehicle was towed to the dealer and held for over two weeks for repairs. 2. Second Incident (Recently): o The vehicle again lost functionality; the gear was stuck in 1st gear, and I was unable to manually shift. o This occurred while driving, creating another unsafe situation. o The vehicle was again taken to the dealer for repair, and to date, I have not been informed of the root cause. Actions Taken: The vehicle was brought to Sarhan, UAE (Sharjah), Al Ghandi Auto after the rst incident. Despite inspections and repair attempts, the issue has recurred, indicating it was not resolved. And I am prepared to provide photographic or video evidence if necessary. Additional Context: • The vehicle is less than one year old and has been regularly serviced on time at authorized centers. The recurring issues strongly indicate an underlying reliability or manufacturing defect. Due to the severity and recurrence of these failures, I refuse any further repair attempts. I formally request either a full refund or a replacement vehicle, as this is unacceptable for a new car. Please acknowledge receipt of this complaint promptly and advise on the next steps for a swift resolution. Sincerely, [XXX] Phone: [XXX] Email: [XXX] Location: Sharjah, UAE INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Transmission Valve Body physical failure causing jerking and abruptly reducing speed to 30 MPH. Vehicle is available for inspection Safety of driver and passengers included abrupt deceleration changes risking physical injury to persons and sudden loss of control of vehicular speed/acceleration risking accident/collision with or by other vehicles. Vehicle has been inspected by dealership and is awaiting new part for 100+ days Warning indicator for service check illuminated but then reset and turned off without incident. Issue with driving occurred with second incidence of service check warning, and vehicle was taken in for inspection/service.

The ignition key intermittently will not extract. I'm seeing a number of complaints on-line regarding this. I have to often restart the truck back up or forward, turn the steering wheel hard left and right, then put in park to extract the key. I believe this is a danger as you would have to leave the key in the ignition of you cannot extract it. This happens multiple times a week.

Component: Shifter Assembly & jumper harness Safety concern: Can't turn off vehicle - Carbon Monoxide poisoning, physical safety when parking not at home, as I would have to leave vehicle running... Message in dash was present when I brought vehicle to dealer. Dealer also replicated No inspection other than dealer. Part returned to me. Warning message has been coming on for past 60 days or so, progressively getting more frequent I receive a 'shift to park' message in telltale after I have shifted to park. At times, vehicle will not shut off until shifter is manipulated for several minutes. I have concerns that I cannot park vehicle in garage, if I cannot shut it off. GM is well aware of issue, but has yet to recall them. Dealer actually had replacement shifter in stock for a same day repair.. I was charged $778.98 for the repair, and GM's customer assistance center response to me simply was to file a complaint with NHTSA. My wife does not feel safe driving, as there is no guarantee vehicle will turn off. Dealer replicated issue when I brought to dealership. Dealer has replaced part and has them. Warning lights only appeared when problem reared itself, initially began about 60 days ago, but is not occurring on approximately 2 of 3 shut downs.

Radio display not working Third row seat won't disengage because of the cable wire being stretched out. Can't remove third row seat. Rear hatch leaking water severely No accident, bought car from Causley GMC in 2024 in Michigan

My 2019 GMC Sierra Denali shut off suddenly while I was stopped in traffic. The engine died, the steering wheel locked, and the dashboard displayed warning messages including “ESC,” “power,” and another I didn’t catch. The truck would not restart despite attempts. The check engine light is now on. This happened without warning, and I had no prior mechanical issues. The vehicle is well maintained, garage-kept, and recently received a full service including oil change, brake work, and 75K-mile recommended service. I fear this is related to a known issue affecting other GMC engines under investigation for sudden power loss.

The front windshield wipers suddenly stopped working while I was driving on the freeway in moderate rainfall on [XXX]. I wasn't able to see through the windshield. I will call GMC in Roseville MN on Monday, June 9, 2025 to request a service date. I waited until the rain was lighter, so I could drive from Willow River Rest Area to Moose Lake, 19 miles. It was inspected at the repair shop, Federated Co-Ops Moose Lake 017, 100 Arrowhead Ln, Moose Lake, MN 55767. (218) 485-4409. He didn't have the part to make the repair on June 6, 2025. His note: Removed engine plastic trim and wiper transmission. socket on wiper transmission popped off. reinstalled. recommend new wiper transmission. There were no prior indications or issues with the wipers not functioning properly. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The seatbelt latch for the middle seat in the third row will not latch. Big safety concern when 8 people are riding because that seatbelt cannot be used. We have not yet taken it to a dealer. We rode with 8 passengers and did not see any warning lights when that person was not buckled.

Transmission went out at 4,150 miles vehicle was having hard shifts and slipping