GMC Complaints

- vehicle started misfiring, ECM, valve timing code, throttle system code, data system, gateway, module,. Vehicle is available and currently at the GMC dealership for continued diagnostic. -this happened on the freeway and out of nowhere the vehicle started shaking, rough, losing power and acceleration, I had to cut someone off on the freeway just to get over to the right shoulder and turned off the vehicle called a tow truck and haven’t been able to use the vehicle since. Vehicle is unable to be driven due to safety issues of increased acceleration and loss of power, intense shaking. -the vehicle is at the dealership now, prior there was a diagnostic performed by a different dealer, and it has been confirmed. -the vehicle is at the GMC dealership now. -ECM check engine light came on prior to the vehicle misfiring and other codes coming up.

Current Unsafe Conditions: Post-Replacement Active Safety Failures. The vehicle presently exhibits two distinct categories of active, ongoing, and dangerous safety failures, both of which were introduced as a direct result of the engine replacement performed by Monument Chevrolet: (a) Severe Drivability Failure. Between approximately 1,500 and 5,000 RPM, the engine repeatedly and without warning lunges forward, drops all power, and lunges again — cycling in this manner between three (3) and six (6) times before stabilizing. This behavior occurs across all gears and driving conditions, which creates a severe and unpredictable hazard particularly when merging into traffic or accelerating onto highways. This failure constitutes an immediate and ongoing risk to the safety of myself and other motorists. (b) Complete ADAS System Failure. The frontal crash response warning light is permanently illuminated on the instrument cluster, rendering the following federally relevant safety systems entirely non-functional: (i) Automatic Emergency Braking / Forward Collision Alert; (ii) Cruise Control; and (iii) Lane Change Assist / Lane Control System. All of these systems were fully operational and properly functioning before the vehicle was submitted for the engine swap. Their failure is an assembly defect introduced by Monument Chevrolet during the course of the repair and constitutes a warranty and safety defect for which General Motors, as the manufacturer and warrantor, bears full responsibility. Medical Hardship and Urgency. This vehicle is my sole personal transportation. It is essential for travel to active medical appointments and upcoming medical procedures. The ongoing failure of General Motors and its authorized service network to restore this vehicle to a safe and fully operable condition has created a serious hardship that directly affects my ability to access needed medical care. Yes, it was driven by a service department supervisor. He did experience the issues.

I bought this truck from a reputable GM dealership 2.5 weeks before this happening occurred. Tires only had 50k miles on them when they were rated for 80k miles: the front driver side Ttire ruptured while on major hwy in texas. No signs of air loss and the road was clear of any debris. Steering started to lightly shake and eventually came to a violent shake, then the front driver tire ruptured. Uncontrollable steering from the rupture caused the truck to slam and scrape into the concrete dividing barrier. If it were not for the other drivers around and being then cautioning their driving behaviors, this may have resulted fatally. Other drivers and my self may have easily collided with each other on a major traffic highway. I’m still extremely mindful of this happening again. This caused me as a customer, originally thinking this tire manufacturer is to be trusted, to not being a customer any longer as well as causing nearly $30,000 of needed repairs. From what I am reading from this site, plenty of other drivers have experienced the same, almost identical happenings. This is a safety issue that needs a recall on this line of tires and the manufacturer should be liable for all costs to the consumer witch includes vehicle rentals, hotel fees and insurance deductibles, s as well as the entire bill of repairs the insurance companies dish out. It appears from all of the complaints, Goodyear is producing unsafe products that is endangering consumers’ lives. Do the ethical thing Goodyear. Stand behind your product and protect, honor your customers. I have requested a subjugation claim with my insurance provider. The ruptured tire and related wheel are in my possession, available for inspection upon request. Police and GM roadside assistance were called as Onstar was prompted.

On Saturday, XXX, at around 3:00 PM, my wife and I were traveling southbound on Interstate XXX toward [XXX] (this occurred in [XXX], just north of [XXX]). We were driving our 2023 GMC Sierra 2500HD pickup while towing our 36-foot 5th wheel trailer. I was traveling at approximately 60 miles per hour, and there was heavy traffic on the highway. Just north of Highway XXX, the passenger rear tire delaminated and went flat. The tread came off the tire, striking the wheel well, rear bumper, and tailgate of my truck, causing significant damage. It also hit the front panel of my 5th wheel trailer. The tread then flew off and struck the windshield of a vehicle traveling next to us, but fortunately, there was no damage to that vehicle. I stopped at a Discount Tire store, where the manager inspected the tire and concluded that it had delaminated, likely due to a defect in the tire. There were no warning signs before the tire failed. Before driving that day, I checked the tire pressure on all tires. According to the information on the tire sidewalls, the rear tires were set to 80 PSI before I started my trip. The tire in question was an [XXX] Goodyear Wrangler Trailrunner AT with DOT#[XXX]. I have contacted Goodyear Tire, and they have since picked up the tire for inspection in their lab. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

When the gas is mashed to accelerate, the car does not want to go. It has left me stranded and rolling in the middle of traffic. I am scared to drive it.

Ongoing issues with Steering pull to right, and brake pull to hard right when applying brakes, which also turns steering wheel to right upon application. Have to keep steering wheel towards left with constant pressure to go in straight line and when braking. Driver has to be aware of changing road conditions that could affect that. Multiple inspections at multiple dealers have found no obvious issues, and multiple alignments performed, with tires also being replaced have had no success in correcting issue. Front suspension starting to feel loose due, and rear suspension squeak when going over bumps. Also recently found rear axle is shifted slightly to right. Suspect all are related. No parts replaced to date other than the tires. Happens daily. No accidents to date. Daily driver with long trips at times. Steering pull Issue has present since new but everything else has occurred since about 1800 miles and has progressively become worse. Conditions becomes worse at highway/freeway speeds of 65 to 80, but occurs as low as 10mph. Going back to 3rd dealer to look at it again. Truck is 2026 with 10,583 miles.

About 6 times during higher speed operation 80+km/hr during a downshift, the rear wheels lock up causing panic from screeching tires and sudden deceleration. Extremely unsafe. The vehicle is in with the dealership and as suspected, they can't find any issues with codes or transmission pressures. We even have a sound recording of the tires locking up. Typical symptoms of the valve body failure. Hopefully there's parts available soon.

My 2015 GMC Sierra 1500 SLE has the 6L80 transmission. While traveling on the interstate with my fiancé, the transmission failed. It was towed to a garage and they informed me that it needed to be replaced.

"While driving, the vehicle suddenly experienced a flashing check engine light, an Electronic Stability Control (ESC) warning light, and violent steering wheel vibrations. The vehicle suffered a severe loss of power and misfired, creating an immediate traffic hazard. The dealership diagnosed the issue as a catastrophic mechanical lifter failure on the 5.3L V8 Ecotec engine with Dynamic Fuel Management (DFM). Despite the dealer replacing an entire bank of lifters, the engine continues to misfire and vibrate. This premature valvetrain failure at only 36,000 miles is a known design defect that causes sudden engine stalling and disables critical safety features like stability control while the vehicle is in motion, presenting a severe crash risk."

The contact owns a 2026 GMC Terrain. The contact stated that after a software update was performed, while driving at an undisclosed speed, the message "Departure Lane Limited due to the Trailer" was displayed. The failure affected the blind spot warning system. The warning light failed to display while approaching a vehicle on the blindside and erroneously operated while there were no vehicles on the side of the vehicle. Additionally, the "Rear Cross Traffic Warning" light was affected by the failure. The vehicle experienced hard braking while there was no other vehicle nearby. The dealer was contacted and diagnosed the vehicle with sensor failure caused by an impact to the sensor. The vehicle was not repaired. The manufacturer was made aware of the failure and referred the contact to the NHTSA Hotline to report the failure. The failure mileage was approximately 11,350.