2023 GMC Sierra 1500

While entering the highway from a downward slop exit ramp and towing a trailer, my truck shuddered hard and briefly locked up the rear axle. It immediately went into limp mode with a message that driving speed will be reduced. It also wouldn't shift past 5th gear. When the event took place, the OBD2 generated over 20 trouble codes. My local dealer advised I could drive it to them for repair. Upon dropping it off, they now advise it's NOT safe for driving and they have no eta on the parts to repair the issue. It's now been at the dealer for a week with no update. This is a well known issue that GM refuses to repair or provide a reasonable timeframe for repair. There are countless videos such as this one that show what happens when this takes place. [XXX] [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Tailgate opened/unlocked while parked during rain and light snow. The tonneau cover disguised that the tailgate was open (held it up just enough so it was not visable). The tailgate fell open while driving but went unnoticed. Several large and expensive items were lost out of the back of the truck which is used as a work truck for electrical services. This has happened twice on the roads. Now the tailgate is physically checked before driving to ensure it will not fall open. The incident was mentioned to the local GM dealer but we were told our model was not part of the recall. Our next call will be to GM directly to try to remedy the problem and hopefully recoup the items lost.

On the highway, the engine suddenly stopped working. Everything turned black. While driving, the screen turned back on but the motor did not start again. I pressed the breaks and the start button to turn the engine back on, while still driving on the highway. It turned back on but then stopped again before I had time to pull to the side of the road. I did the same again and got to bring the car to the side of the highway. It started and stopped several times. I got it to run again so I exited the highway. It turned off again once I was off the highway. I got to drive it slowly to the dealer. He said it had never happened (which is untrue, I found out it is a recurring problem on the GM 6.2 liter). I had brought the car for service to the same dealership about a week prior to the incident. At that time, I told the dealer that the motor was making subtle weird noises. They serviced the car and gave it back to me stating that everything was ok and that nothing showed on their computer. When I picked up the car after the shutting off incident, I was told that their system showed prior issues but that nothing needed to be done since it was not detecting any problem at the time of pick up. About a week after I picked up my truck (after the shutting off issue was supposed to have been taken care of), I returned because I was still noticing the noise. While on a test drive with a GM mechanic, the motor suddenly started making very loud clicking and squeaking noises. He told me to stop right away. The manager at the dealership told me I would get a new motor because there was a recuring issue with the GM 6.2l. After a week, he said only some parts would be changed and that GM would not replace the whole motor. I told him I did not feel safe driving the truck and he said GM decides what to replace not me. I read online that the motor and all oil filters, ducts etc need to be replaced to avoid debris and future problems. No warning light ever went on. Terrifying experience.

The tailgate on my truck opened while I was driving and I was unaware until I got to my destination. I had a utility trailer attached at the time and my tailgate was damaged from the jack on the trailer. I thought maybe I didn't latch the tailgate but it has been several days since I opened it. The following day the tailgate dropped two more times in less than a mile. I see there is a service bulletin and recall on most GM models but my truck is not included. I made a service appointment at my local dealership for them to inspect. The service writer already stated that my truck has no open recalls. I feel this is a safety issue first and second my truck has body damage. I use my truck as a truck and usually have stuff in the bed. My truck is completely stock with no modifications except a GMC bed cover that I purchased at the dealership. I'm hoping for the best on Monday 2/17/25 when I take my truck in to be inspected.

The contact owns a 2023 GMC Sierra 1500. The contact stated upon attempting to start the vehicle remotely, the lights illuminated; however, the engine failed to turn over. The contact stated that upon pressing the Push to Start button, the message "Service Braking System" and other braking system messages, and message that the "Top Speed 43 MPH" were displayed. The check engine warning light was illuminated. Additionally, the contact stated that the vehicle experienced reduced braking while driving at various speeds. The vehicle was taken to the dealer where an unknown software update was performed; however, the failure recurred. The contact stated that the failure occurred intermittently. The vehicle was taken back to the dealer, where a service representative scanned the vehicle and informed the contact that diagnostic trouble codes were retrieved; however, the dealer later informed the contact that the failure could not be replicated. The contact used a scanner to scan the vehicle and retrieved diagnostic trouble codes. The manufacturer was notified of the failure and a case was opened. The manufacturer later informed the contact that they could not assist because the dealer stated that the failure could not be replicated. The failure mileage was unknown.

I have been trying since day one of my brand new 2023 Sierra Denali pickup truck hence I spent a $100 K plus OEM accessories at the dealer ! This complaint is in reference to the safety part of the brake trailing that disconnect and lose light and brakes ! I have Spent insane times at the dealers and have complained to the GMC Executive offices with Nothing but excuses and Absolutely Zero Help from GMC Cooperate but continue to go make appointments at the dealers ! This is Safety complaint and they are not taking this seriously at all ! There is defiantly a ongoing issue with either the computer onboard or the trailer Module ! I am not a engineer but again this is a safety Issue that needs to be looked at ASAP ! I do not feel safe driving the truck !

The contact owns a 2023 GMC Sierra 1500. The contact stated while driving 65 MPH with the cruise control engaged, the instrument cluster was blinking and then went black. The contact stated that the failure was intermittent but had become a recurring failure. The contact also heard a chirping sound when the instrument cluster went black. The contact had taken the vehicle to a dealer and was informed that there were no failures with the electrical system. The contact was unsure if a diagnostic test had been performed. The vehicle was not repaired. The manufacturer was informed of the failure. The failure mileage was approximately 56,000.

Engine goes to limp mode multiple times 3 of which happened getting onto the highway and almost creating an accident due to the reduced acceleration mode. CODe u0656 00 popped up each time. Dealer has yet to rectify due to lack of appointments… making me keep the vehicle saying it’s drivable but each time randomly goes into the reduced acceleration mode every restart. (Blasius GMC Branford CT)

Approx 17 months after purchase, tailgate release button (the lower button on the tailgate that is used to open (fully) the tailgate) stopped releasing the tailgate, however tailgate releases randomly when opening one of the truck doors. Based on the "fix" that has been subscribed for existing Chevy & GMC trucks with recalls for this same problem (although my truck isn't covered by current recalls) , my mechanic has ordered a new tailgate release switch (or whatever it is called) which they are installing tomorrow.

I bought truck brand new one week later the tailgate opened while driving and hit the trailer and destroyed the tailgate. So I bought a brand New tailgate and repaired truck. Few months ago it happened again all my tools flew out into the highway almost caused a major accident and destroyed my saw and tools got thrown all over the road. Last week it opened again and destroyed the new tailgate I bought. The dealer is aware, gmc is aware and no parts to fix it or does anyone want to help me just let me drive a truck that is so unsafe. It's all over the internet this issue people are saying there tailgate opens while driving and gmc made a statement saying they are aware but not helping me. Sold me a truck for alot of money knowing it's a major dangerous defect that can cause major damage and serious injury on the road.