2016 GMC YUKON Complaints

1. My vehicle is having transmission issues with shuddering and shifting. M5U RPO code 8L90 transmission. 2. My safety and the safety of others is a concern if the transmission is not working as intended my vehicle could be at risk an accident that could be avoided. 3. The problem has not be reproduced or confirmed by a dealer I work on my own vehicles and I am going to repair this issue myself if able. 4. There are no trouble codes on my vehicle when scanned with an OBD2 scanner.

The contact owns a 2016 GMC Yukon. The contact stated that while driving at an undisclosed speed, the brake pedal was depressed; however, the vehicle failed to stop as intended. The contact stated that there was an abnormal sound coming from the vehicle and the ABS warning light was illuminated. The contact stated that after several attempts, the vehicle stopped. The vehicle was taken to the dealer; however, the vehicle was waiting to be inspected. The contact stated that an unknown recall repair with a similar description was completed in 2024; however, the contact was informed that the repair was not covered under warranty. The manufacturer was made aware of the failure but provided no assistance. The failure mileage was approximately 136,000.

The contact owns a 2016 GMC Yukon. The contact stated that while the vehicle was at the inspection station for an inspection, the accelerator pedal was depressed; however, the vehicle failed to accelerate as intended. The contact stated that the transmission had seized, and the vehicle failed to move. In addition, the check engine warning light was illuminated. The contact stated that the failure had occurred immediately after an unknown device was attached to the vehicle while being inspected. The contact informed the inspector of the failure. The contact was advised to contact the NHTSA Hotline to report the failure. The dealer was not made aware of the failure. The vehicle was not diagnosed or repaired by an independent mechanic or the dealer. The manufacturer was not made aware of the failure. The failure mileage was 119,637.

After my child had thrown up all over the car seat her father had taken her inside to clean up and I took the car seat apart to throw the pieces into the washer to clean them. The harness strap did not come out fully clean so I contacted Graco for a replacement piece and I was told that they don’t replace those and that the strap being removed totaled my car seat. It has a woven material tab that goes up through the hard plastic base and locks in by opening itself. It’s essentially a T in the material so it can be folded to go back through the hard plastic base. I was told that since the manual doesn’t provide instructions regarding that piece that I should know it’s not to be removed. No where in the manual, on the car seat or on the strap says it’s not to be removed. I did not damage/break/cut any pieces to get it in or out of the car seat. I was a mom in a panic trying to clean the car seat as quickly as possible so I could tend to my sick child. There were no warning signs telling me anywhere not to remove it. I don’t want other parents to do what I did and have a totaled car seat that they continue to use. I did not have the manual at the time of removing the pieces for cleaning but I have since located the PDF and read through all 96 pages.

The contact owns a 2016 GMC Yukon. The contact stated that while driving at an undisclosed speed, the brake pedal became inoperable and failed to engage properly, with no warning lights illuminated. The contact also stated that while the vehicle was parked, excessive force was needed to engage the brake pedal and stop the vehicle. The contact stated that the failure nearly caused the vehicle to collide with another object. The dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 108,959.

Transmission went out very early. Had to get it replaced whenever I reverse. I have to really smash on the break in order for it to stop if it does stop so somethings wrong with the breaking whenever I hit a bump the left side suspension feels like I’m a lose control and sometimes my radio works and sometimes it doesn’t I’ve been trying to work with dealers I have extended warranty on it. They’re saying it’s not covered something about the brake pump is covered, but the belts are not. The transmission was put in only because it left me stranded. Otherwise I would’ve been stuck paying for that. The dealership actually helped me with that. My GPS turns on and off sometime. I’m not sure if it’s electrical

My wife was driving down the highway and out of no where there was a loud taping sound, the vehicle started running real bad (skipping), the vehicle lost power and she lost control of the steering. As a result, she ran off the road into a ditch. this is a known concern with the 6.2 liter engines and all signs are pointing to lifter failure. She could have ben seriously injured and GM is responsible for this.

Ticking sound coming from engine, possible damaged camshaft lobe due to lifter roller failure. It can cause sudden engine failure, significant power loss, and unexpected stalling while driving, increasing crash risks. The issue is linked to AFM (Active Fuel Management) system failures. The problem has been diagnosed by dealer service department. No warning lamp or message, problem first appeared 7 April 2026.

I am submitting this complaint to report what I believe to be a serious and systemic safety defect involving GM 6.2L engines equipped with fuel efficiency systems such as Active Fuel Management (AFM) or Dynamic Fuel Management (DFM). I have experienced catastrophic engine failure in two separate GMC Yukon Denali vehicles with nearly identical symptoms, which strongly suggests a broader design defect rather than isolated mechanical issues. My first vehicle, a 2015 GMC Yukon Denali XL, developed significant engine performance problems consistent with known lifter and camshaft failures widely reported in GM vehicles using these fuel efficiency systems. Due to ongoing reliability concerns and the financial burden of potential repair, I was forced to trade this vehicle at a loss. My second vehicle, a 2016 GMC Yukon Denali XL equipped with the same engine platform, suffered sudden and catastrophic engine failure in February 2026. This failure occurred abruptly and without meaningful prior warning, rendering the vehicle inoperable and creating a potentially hazardous situation. Sudden engine failure of this nature presents a significant safety risk, particularly if it occurs at highway speeds or in heavy traffic. An oil service had been performed on this vehicle in December 2025 at a Jiffy Lube franchise. After the failure, an independent service provider documented that the oil fill cap had been left loose. However, the Jiffy Lube franchise and its insurance carrier have denied responsibility, asserting that the engine failure is attributable to known defects and reliability issues associated with GM’s fuel efficiency engine systems. As a result, both the manufacturer and the service provider are denying responsibility for a catastrophic mechanical failure that has serious safety implications. This leaves consumers exposed to sudden engine failure risk with no meaningful recourse. Based on my direct experience with two separate vehicles exhibiting similar catastroph

Vehicle been in the shop 3 times. [XXX] suspension light repeat come on. Working with warranty company. Light came on again 3 more times after Vehicle left the shop INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)