Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2012 GMC Acadia owners, lightly cleaned up (personal details are redacted by NHTSA).
Was waiting on dealership to catch up to bring in for a transmission problem. I know it is transmission related due to not wanting to shift properly and the fact my friend has same make and model only about 100000 more miles than mine does was doing same symptoms and she took to 3 or 4 mechanics and all said nothing wrong..no codes show up...needless to say after about 2 months it stalled out on her on interstate with speed limit 75 and she barely moving. I myself was at a sharp curve in turn lane waiting on traffic and when I braked to stop it made horrible sound and felt like brake was pushed through floorboard. When I was clear to go i push accelerator down to the floor and am barely inching along and am now stuck in the road in a 90 curve where its hard to see traffic coming. This was very scary and traumatic having this happen. …
The contact owns a 2012 GMC Acadia. The contact stated that while driving 70 MPH, the RPM would rise to 4,000 however, the vehicle failed to respond as intended. The check engine warning light was illuminated. The contact pulled over to the side of the road and inspected the vehicle and became aware of smoke coming from the engine compartment. The vehicle was towed to an independent mechanic where it was diagnosed that the engine block, camshaft, reverse gear, and transmission housing needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 158,000.
The contact owns 2012 GMC Acadia. The contact stated that the vehicle was taken for the state-mandated smog test and he was informed that there was an issue with the transmission. The contact took the vehicle to the local dealer to be diagnosed. The contact was informed that the transmission needed to be replaced. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 104,000.
The contact owns a 2012 GMC Acadia. The contact stated that the vehicle failed to release from low gear while at a stop. The transmission was backed up. The engine light was illuminated. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was contacted, who confirmed there were no recalls. The failure mileage was approximately 213,766.
I noticed shuddering while driving my car and when I took it to my mechanic upon test driving and inspecting it he realized the torque converter is not strong enough for the size of the car. He informed me driving it with the improper size will cause it to shudder and accelerate or not accelerate correctly while driving and cause slipping while shifting gears. Those issue have been happening the entire time I've had it and if the car slips and goes too fast or slips and loses power it is a danger to me and the other cars on the road. There were no codes or warning indicators while this is happening.
No warning light when transmission went out. Traction control/stabiltrac service light came on, doors locking and unlocking, not stating what gear acadia was in. Check engine light eventually came on, after it stalled twice on highway. Vehicle is at gmc dealership service department and they are saying its not communicating and are checking wiring harness wires. I have replaced transmission and torque converter and now i dont know what to expect now. Only had it for 3 years so far. I almost got rear ended when it stalled twice before backfiring and a rough swift shift.
We just purchased this 2012 gmc acadia about 30 days ago and every day we drive it we have this issue.. from a complete stop when pressing the gas the truck feels like it has no power starting to go until the rpm's each maybe 4500 then the truck will jerk and studder through the intersections. i feel like we are going to be in a MAJOR accident while proceeding through intersections. the dealer states there is nothing they can do. there is absolutely something wrong when it jerks and stutters to move
The automatic passenger side window does not work anymore, it went out a couple months after I bought it. I have always done maintenance on my vehicle, oil changes, tires, etc. and the timing chain went out on it for some unknown reason. Very pricey to fix. I would hate to be stranded with my 6 grandchildren with. With all the complaints on the timing chain, this should be a recall.
The transmission has all the symptoms of a broken wave plate and/or torque convertor as reported in the first generation T75 transmission service bulletin. This started occurring at 120K. I know the service bulletin was for the 2007-2009 models but the 2012 had the same exact transmission and waveplate. The car feels like it's going to shudder out and die on the highway.
Ratle sound in the engine thinking it may be the timing chain. Code p0430 came on stating catalytic converter bank 2 needs replaced. We replaced o2 sensor downstream on bank 2 code was cleared by shop. After driving a few miles same check engine light came on and i took it to the shop they hooked it up to run the code and it was the same p0430 again
Transmission complaints in other Acadia years
Frequently asked questions
How common are transmission problems on the 2012 GMC Acadia?
NHTSA has 43 complaints about the transmission & drivetrain of the 2012 GMC Acadia, 15% of the model year's 296 complaints.
Is there a recall for 2012 GMC Acadia transmission problems?
No. NHTSA lists no transmission & drivetrain recall for the 2012 GMC Acadia, though it has 5 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2012 GMC Acadia transmission problems start?
Half of the complaints with a recorded mileage happened before about 99,000 miles, and 17% before 25,000 miles.
Is it dangerous?
Owners linked 2 crashes, 0 fires and 0 injuries to transmission & drivetrain problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.