GMC Complaints

I bought my 2026 GMC in April. Several times the audio doesn't work work. When this happens audio related safety technology is affected too including turn signal sounds and back camera audio also. A person walking behind the truck can be seen on the screen but no warning beeps are heard. When backing up the warning for getting too close to an object also doesn't work. I called the dealer in early May and was told that this was a known issue and that it needed a software update. took the truck to the dealer on May 8th and the software update was performed. When the update had been completed when I started the truck after the update there was no audio. I told the service advisor it was currently happening and she took it back to the technician. They disconnected the battery cables to reset the system and told me to do that in the future until the issue is resolved. I opened Case #100978480 with GM on June 1st because I wanted to be sure that GM was also informed of the issue. I was hoping they would be proactive and report back to me what they were doing to resolve this issue. Instead I was told that I need to call the dealer and the dealer would call GM because an update might be available but dealers wouldn't be informed and wouldn't check unless I called.

The vehicle is equipped with “rain-sensing windshield wipers” but they do not work due to poor design. They should not have failed this quickly (33,000 or so miles). The windshield wipers must be manually activated because of this defect, but since the manufacturer thought they would be automatic, they made the manual activation very hard to access. It is very dangerous trying to activate them while operating the vehicle because A) your eyes are off the road for an extended period in poor conditions and B) the control is in a hard-to-reach area. You have to turn the nob 6-7 positions to put the wipers on low or high, and for the first 5 positions the windshield wipers don’t activate.

The panoramic sunroof has a substantial leak, even though the 2023 vehicle only has 33,000 miles on it. The drain lines are clear but water continues to significantly leak out of the rear passenger seatbelt housing onto the seatbelt. There is also significant water drainage through the rear interior lights onto the upper legs of rear passengers (children in car seats), causing a severe electrical hazard. The leaking caused by the drainage defect affects the interior lighting, the seatbelts, and is a potential electric hazard. This seems to be a common occurrence and the manufacturer should repair their defective products. The drainage pipes are obviously either not assembled correctly or the materials don’t hold up. This should not be occurring in a $55,000 vehicle with 30,000 miles. I have multiple videos I can provide but the file sizes are too large to upload, so I took screenshots. I am going to pay for the repair but I should be reimbursed by GMC.

2021 GMC Sierra after purchase at 4,700 miles had issue with the lifter rods and were replaced at that time. Now the truck has a little over 67,000 miles and once again have the same issue. This appears to be a known issue with this truck and the 5.3L engines. The truck is in repair and since it is slightly over its warranty of 60,000 miles. The dealer will not cover the repair. Seeing that this is an ongoing and known issues with service bulletins it seems that this should be a potential recall. We were lucky that we identified the issue early and were able to get to the dealer to fix. Otherwise we could have broken down in the middle of our daily commute in the expressway.

My car started making a knocking noise under the hood 2 days prior to it breaking down (6/19 & 6/20). On 6/21/26, I was driving down the interstate WITH my kids in the car and it shut down on its own. Lights came on my dash and the vehicle quickly slowed itself down and when I pulled over to a complete stop, the vehicle shifted into neutral and shut off. I was not able to crank it back up and had to pay a tow company $243 out of pocket to tow it to our local dealership in town. My insurance only covers $200 for towing. I am a week without a vehicle and just found out Friday (6/26) that a new motor will have to be ordered but it is on back order with no idea on when it may arrive. I cannot get an answer from GM or my local dealership on if a rental will be provided. I cannot make 2 car payments but I also have a job and cannot proceed without having a vehicle to drive. This has put me in a bind for a week already with no solution in sight. I expect GM to fix my problem asap since it is theirs to fix!!

Without any indications of a problem our transmission began making a loud whining noise. The evening before it was fine and the next morning on startup the noise just began. The Vehicle only has 45,000 miles on it and the transmission had been serviced at the recommend manufacturer interval. Took it immediately to my auto repair shop where it was diagnosed as a transmission failure (they has seen this before) and told not to drive until replaced due to safety issues related to the failure. Unfortunately, due to a shortage of these needed 10 speed transmission I waited over a month for the vehicle to be repaired. The shop contacted GM to inquire about any warranty help but was told there was none.

The center screen (infotainment), which shows controls for cabin climate (A/C, heat) and many more functions of the vehicle fails to turn on at random times. It is available for inspection. The external air temperature is in the upper 90s; temperature inside the car’s cabin is easily 115 or higher. This makes safe operation of the car not possible. Additionally passengers cannot occupy the vehicle safely at these extreme temperatures. The problem has been reproduced by dealers. UNKNOWN whether the components have been inspected by the manufacturer. No warning lamps or lights.

There is a water leak in the rear passenger compartment of my vehicle. Unsure where water is coming from. Continued leaking poses a risk to my safety as I may be exposed to black mold as well as anyone else who is riding in my vehicle. The problem hasn’t been addressed by the dealer yet but this is a known issue. At this point I have spoken with a representative from the service department at the dealership but cannot get an appointment for several weeks. I was also advised that the problem would need to be diagnosed before being addressed at my cost due to being outside of the warranty period. There were no warning lights or any other signs that this is occurring and was only discovered because I was putting something in the back seat on 6/26/26.

This truck has the 6.2 GM engine. While driving it late at night at approximately 28mph the engine blew, leaving the truck in the lane and unable to move. This was very dangerous since there was no warning and it just died. The truck receives regular maintenance by GMC and was tested to see if it was a “bad engine” and we were instructed that it wasn’t. GM said it will take 4-8 weeks to get an engine and the value of the truck to trade in is very low due to “marketing issues” which in my opinion is their issue not mine. I am battling stage 4 cancer and just had an operation and need a car to go to the doctors. They have officially said that they don’t have a truck to loan me. This has been going on for years apparently and the government is not doing anything to rectify it for the US tax payers per my research. I need a truck and GM said that they would get back to me within 24-48 hours, we are way past that. What is the government going to do, these trucks are not safe. What if I was traveling late at night to snowmobiling and it blew, it would be a different story. Need some help

Shortly after purchasing my 2019 GMC Acadia with 52,000 miles on it, my wife parked the vehicle in our driveway and shifted the transmission into Park. When she pressed the push button to shut the vehicle off, the instrument cluster displayed a "Shift to Park" message even though the shifter was already in the Park position. Because the vehicle did not recognize that it was in Park, it would not shut off completely. The radio remained on, and the doors could not be locked. The only way to get the vehicle to shut off was to repeatedly shift from Drive to Park until it finally recognized Park. This occurred multiple times. After researching the problem, I discovered that many other GM owners have experienced the same "Shift to Park" failure. I believe this is a widespread defect that should be investigated because it can prevent a vehicle from shutting off properly, leave electrical accessories powered on, drain the battery, and prevent the vehicle from being secured when parked.