GMC Complaints

My husband just did an at home oil change on the car not long before the incident. Unfortunately my car was barely under 3,000 miles since the oil change and we were going to change the oil again when my engine died mid drive on the way home. There was no oil in the car due to high oil consumption and no coolant either. High oil consumption was not reported and not disclosed to me before and a broken guide for my timing chain leading to total engine failure just after I started to exit the highway. Had my car died any sooner I would have crashed. Or wrecked with another vehicle. GMC and the dealership I got the car from did not properly disclose this safety risk to me when I purchased the car and no recall information was ever sent out. The high oil consumption causing engine failure has been a part of a class action lawsuit for these vehicles before and THAT was not disclosed to me either at any point. No notifications of low oil or other issues aside from a check engine light came on for my vehicle when I was driving. I dont know how fast I was going as I was applying the brakes to my car for a traffic light.

The contact owns a 2015 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the brake pedal was firm and unresponsive, and the vehicle was difficult to stop. The vehicle eventually came to a stop with the ABS warning light illuminated. The vehicle was driven back to the residence. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 132,235.

Engine loss of power many different engine code took it to the dealership. Now they say lifters, rockers are loose and worn,broken,the cylinder 5 misfire, engine needs rebuild at 88,000 miles. Dealer wants over ten thousand dollars to take apart and repair

My wife and child drove the car to the grocery store and parked the car l. When she returned to leave , the car would not start and flashed a warning with key fob not detected and some kind of security light warning. The instrument cluster told her to place the key in left console cup holder to crank the vehicle . This did not work either .I drove the second key fob to her to determine if it was a key fob issue and the 2 nd key did not work as well. Called dealership and service requested the car being towed. Tow truck didn’t feel comfortable with the removing the vehicle as it was sitting due to space in the parking lot. They dispatched a small tow truck , but in the meantime I disconnected the battery cable and waited about 15 min. The car cranked and I immediately drove it to dealership. There was no code shown at the dealership and this was the first time they have had dealt with this issue. The mechanic drove the car the next day and the same situation happened again , except this time the key fob worked after several failed attempts . I feel that this is a safety issue because the car failed to operate and had no manual ability to operate without the electronic system functioning properly and this could have happened anyway and stranded my wife and child . A few months before in an unrelated incident , the power trunk malfunctioned and had to be reprogrammed . It would not operate except manually . Car is currently at dealership still being evaluated .

Engine failure occurred while transferring passengers in a busy road. The vehicle started making noises at first I thought it was a belt that might have been going bad. I looked at all the gages which did not indicate any issues with the battery or oil pressure or any vital issues that might show and merged to the right lane. Less than 2 miles down the road engine shut off and I was able to coast into a parking lot. I took this vehicle as requested for the recall and the only recommendation was to start using OS 0W40 and a new oil cap indicating the required oil type. These vehicles should be pulled off the roads, they create a huge safety hazard on our roads and sooner or later someone is going to get killed.

During day to day driving when the truck is accelerating from a stopped position there's a massive clunk or hard shift from either 1st to 2nd gear. have also heard similar complaints from other 2015 sierra 1500 owners saying the transmission is having a hard shift on acceleration from a stop. Have seen possible issues with the TCCM

Transmission has failed twice in 2023, dealer carried out repairs but still the Transmission started shuddering after every 1000 miles, truck has been in service centre for almost 12 times for the repeated issue but no permanent solution, after my bumper to bumper warranty got over in 2025 September again service Transmission sign appeared and got my valve body replaced on January. after a month on feb the same message appeared again to service transmission and they refused to cover the issue in warranty and asked me to pay almost 7k dollors to get it repaired.

I have had shuddering on the highway and a few hard random diwnshifts. Last week I went to start my truck and the transmission started grinding and rattling. I was told after towing to the dealer it needed a transmission due to pump not getting enough fluid and had failed. I was told I needed to pay, even though the part causing the problem had a extended 150,000 miles and the subsequent pump failure is a result of the control valve failure.

This vehicle since early inception of ownership has been brought to the dealer for failure to start, oil consumption and the vehicle stopping suddenly on it's own. There have been 13 service calls and each time the vehicle has been brought to dealer for the problem at hand shortly after that the vehicle was brought back again for the same issue and eventually escalating into other severe problems. The vehicle is unsafe to drive because it suddenly stops without warning, oil is being burned and needs replacement more often than it should. The vehicle recently had to be towed because it stopped and could not be started. The manufacturer claims that there is nothing wrong with this truck. However, this was disputed by a second dealer that examined the vehicle.

This 2024 GMC Sierra Heavy Duty has experienced a continuous pattern of major mechanical and electrical failures since early ownership. The vehicle required a complete engine replacement under warranty at approximately 43,626 miles. Since that time, the vehicle has continued to experience repeated injector failures, control module faults, communication errors, and voltage-related system issues. Current diagnostic codes indicate multiple simultaneous failures including ignition relay feedback circuits, control module power faults, gateway communication loss, brake system communication faults, and battery voltage circuit errors. The dealership has diagnosed a power distribution / fuse block failure at approximately 79,000 miles. These electrical failures affect multiple vehicle systems and raise concerns regarding reliability and potential safety risks due to loss of communication between control modules and possible braking system interaction. The vehicle has been in the dealership numerous times for repairs including engine replacement, injector replacement, control module reprogramming, and electrical diagnostics. I am submitting this complaint due to concern over a potential systemic electrical defect and ongoing reliability issues.