2023 GMC YUKON XL Power Train Problems

I am writing to formally file a complaint regarding a serious and ongoing issue with my vehicle that has placed my safety at risk and resulted in significant inconvenience and financial burden due to General Motors’ failure to honor my warranty in a timely manner. While driving on the highway, my vehicle suddenly began losing power and displayed flashing warning messages indicating that it would not shift into gear or out of gear and that power could be lost. This created an extremely dangerous driving situation and posed a serious safety risk to me and other motorists. I brought the vehicle in for warranty service, but General Motors was unable to honor the warranty repair in a timely manner. As a result, I was without my vehicle for several months while it sat undrivable on the dealership lot. Once the vehicle was finally repaired and returned to me, the exact same transmission-related incident occurred again. Once again, I was left without the vehicle for an additional period of days. This repeat failure has severely shaken my confidence in the reliability and safety of the vehicle. When I picked up the vehicle after the subsequent repair, I was informed by a General Motors technician that the brakes and rotors were most likely pitted and damaged and would need repair or replacement because the vehicle had been sitting undrivable for such an extended period of time. I was explicitly told this damage was expected due to the prolonged inactivity caused by the unresolved warranty issue. It is critical to stress that the vehicle only sat undrivable for such a long period of time as a direct result of General Motors’ inability to honor the warranty in a timely manner. Despite this, I am now being told that the brake and rotor damage is considered a “maintenance issue,” even though a General Motors technician directly advised me that this damage would occur as a consequence of the vehicle sitting for months due to warranty delay

Engine oil level drops significantly well before the oil change interval. Vehicle consumes excessive oil without warning lights or leaks. Risk of engine damage or failure if oil level is not closely monitored. Condition discovered during normal use.

Vehicle has 56000 miles currently and at 47000 transmission had to be replaced due to defective valve body. At 56000 miles, motor was replaced due to broken lifter. The vehicle currently will not start.

While driving the vehicles went into limp mode with a transmission issue. Vehicle was towed to the dealership where I was informed the transmission body valve has failed. Vehicle has been out of service for 3 week so far, still not fixed.

On May 23, 2025, I purchased a 2023 GMC Yukon XL VIN: [XXX] from the GMC dealership.
 At the time of sale, I specifically asked about the active GM engine recall. They assured me the vehicle had been inspected and was unaffected. On October 30, 2025, the engine catastrophically failed on a highway while my family — including my two small children — were in the vehicle. This created a dangerous emergency situation as I had to avoid high-speed traffic. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

OnStar module doesn’t work it went out in January 2025 there’s a 1000’s of other users in the in the OnStar module community complaining of the same issues . When you take it to the dealership they will not assist and will not warranty it out

The valve body failed on 6/4/25. This caused the car to have a sudden jerk and then suddenly decelerate while driving with my children in the vehicle. It could have caused an accident if another vehicle had been following behind. The vehicle has been at the local GMC dealership for repair for almost 8 weeks now, and is available for inspection by 3rd party upon request. The same part failure has been found in the 2019-2022 models. There was no warning to this happening to my vehicle, just a sudden jerk and deceleration. After it occurred the check engine light came on.

Transmission jerking upon acceleration at all speeds. Reproduced and confirmed by the dealer to be a faulty transmission valve body. Part is on back order and vehicle has been returned to me as it is “driveable” as per dealership rep. No warning lamps.

Driving 58 mph then felt like I slammed on my brakes out of no where then sped up on its own to 42 mph then wouldn’t accelerate but rpm was at 5000. Shortly after my reduced power warning came on. Well the next 12 hours I went to reverse and had nothing! Now dealership is saying unknown timeframe for it to be fixed.

SUV appears to get stuck in gear or struggle shifting causing jerky behavior and erratic drivability. Stopped driving and had it towed to dealer. Dealer stated Engine Code P0747 shown. Dealer stated faulty transmission valve body but no ETA on parts. Told to keep driving unless condition gets worse. Vehicle is less than 2 years old and 20,000 miles. Check engine light goes on and off relating to the same condition and sometimes having shift issues.

Cam shaft The problem was corrected by a licensed mechanic

I am formally requesting a complete refund for my vehicle. It has only 6,300 miles, and the remedy provided for the recall does not adequately address the issue. The recall explicitly indicates defects in the engine components (rods/cam shafts) that may lead to a loss of propulsion. Merely inspecting the vehicle and adding thicker oil does not resolve the underlying problem; it only postpones the inevitable expiration of my warranty. Currently, there are no warning lights illuminated, as the vehicle is not driven frequently. The recall raises significant concerns, and GM should be taking more substantial measures than simply applying thicker oil as a solution. This approach feels like a temporary fix rather than a genuine resolution. I have communicated with the dealership, and have been informed there is currently no solution available for this matter. They are awaiting further instructions on how to proceed. I request a more thorough investigation into this issue for an appropriate refund, and I also wish to have this matter documented for future reference.

Multiple issues...I bought the vehicle in Oct. 2023 1. BRAND NEW.... First day I brought the vehicle home there was a whining sound coming from the transmission. The reaction carrier assembly had to be replaced along with all other components. The transmission had to be completely removed from the vehicle and repaired. 2. In May of 2024 I had to have the lifters replaced on one side of the motor. 3. Right now it's in the shop with a blown motor. Yes there's only about 43,000 miles on it and the motor is blown and has to be fully replaced.

I was going about 53 mph and went to pass another vehicle. While in the oncoming traffic lane, the transmission went out. The engine revved up and the gas pedal did not work. The vehicle has been inspected and was found to have a faulty control module that possibly caused the failure within the transmission. The parts are all on "indefinite backorder" and I have a $50,000 loan on a $60,000 vehicle that is now a paper weight.

I was travelling on the interstate at 75 miles per hour and the vehicle started slowing down and completely shut down. The engine warning light then came on and I had to coast to the side of the road. I was on the side of the interstate for about 45 minutes and the vehicle had to be towed. The repair shop informed me it was a complete engine failure requiring a new motor and that GM has an extended backorder time due to this being a widespread problem for these model years with the 6.2L gas engine. The vehicle is currently at the dealership and will be there for several months waiting on an engine.

I am writing to express serious safety concerns regarding our 2023 GMC Yukon XL Denali, which has been in our possession for less than two years and has only 24,000 miles. On multiple occasions, while driving at high speeds on the freeway with our four young children, the vehicle unexpectedly lost power and shifted into neutral without warning. This occurred approximately four times on March 9, 2025, when we contacted OnStar for assistance. Despite their response indicating no alerts on their end, we were advised to reach out again if the issue persisted. Unfortunately, the problem did occur again on March 16th, which prompted us to contact OnStar and have the vehicle towed to the nearest dealership for further evaluation. The service department has since informed us that the motor requires replacement. Upon conducting additional research, it seems this may be a known issue with many vehicles manufactured by GM around the same time. We are deeply concerned by this safety hazard, especially given that the malfunction could have led to a life-threatening accident. While we are grateful that we were fortunate enough to avoid any serious consequences, we believe a solution beyond standard repairs is necessary to restore our confidence in the safety of this vehicle. Our family’s well-being and trust in the reliability of our vehicle are of the utmost importance.

While driving, vehicle threw an error “ reduced acceleration, drive with care”. I had my children in the car when the car abruptly reduced speed and car jerked. It was very scary while driving. It was stuck in 5th gear. I was taken to dealership. Code showed it needs a Transmission Valve Body replacement. Part # 24065353. Dealership has stated part is “on backorder with no ETA of the part”. My car has been sitting on the lot for 17 days waiting to be fixed.

My engine stopped while I was driving. Unable to accelerate and the car will not start and is dead. Transmission light and DEF service lights came on. Luckily I was able to pull over to safety, barely. It was towed to the GMC dealership and waiting for it to be looked at. There were NO warning lights that came on previous to when this happened. This is a HUGE SAFETY concern for GM and it needs to be a recall because many, many others have reported the same complaints.