2020 GMC SIERRA 3500 Complaints

There is a current safety recall N232426400 on GMC pickups including the year of my truck. GMC is saying that my VIN is not covered by the recall. However, I have the multi-pro tailgate and it came open about 6 months ago on its own as i was backing up and it caused me to run into my trailer with the tailgate. I put my tailgate up after moving my truck from under my trailer and then when i went to back up somehow the tailgate popped open and i didnt know and it contacted the top of tailgate while it was down.

driving 65mph on interstate, attempted to change lanes to pass slower vehicle and pressed upon accelerator pedal...truck violently skidded to a stop and sent me onto shoulder, many vehicles behind me swerved to avoid my vehicle. GM wont repair and says since they cant replicate its not really happening. this has happened twice in last 2 weeks.

driving approximately 50 mph when vehicle suddenly made loud bang and locked up rear brakes for 25' coming to a stop in road side ditch, numerous vehicles had to make evasive actions to avoid me and other vehicles. flat spotted tire abut no visible physical damage. sat on side of road for transmission temp to cool down then drove to shop without repeat. called dealer was told the earliest appt was a month away. have not been able to repeat incident so far. this has happened a few times and is becoming more frequent, mfg has tsb issued but indicates they cant assist because my warranty has expired so i will have to pay 225 per hour diagnostic fee. this is untenable and dangerous. this needs a recall and repair ASAP.

driving 45 mph westbound i70 at eisenhower tunnel, vefhicle made loud bang, brakes locked up momentarily slowing vehicle to around 25mph. multiple vehicles had to make evasive manuevers to avoid collision. vehicle released after a 15FT skid. pulled over to safety and inspect for damage, tires were falt spotted but no damage was visible. called dealer servcei and was told to make appt and set for diagnostic. service could not replicate or find damage so I was sent on my way and told if it does it again let us know. I am scared to drive this vehicle its unsafe

driving 65mph when vehicle attempted to downshift itself for no reason when instead the rear axles locked up and made a massively loud bang as if axle fell off, let off gas, smoke pouring from rear tires, skidded about 8 feet, it released then locked up 2 more times within 30 secs before I could get off road out of traffic flow. mfd has a tsb for this issue(#21-NA-275 GM) not sure if its transmission or braking system Dealer service could not replicate and told me it was probably my trailer(wasnt traveling with trailer) no warnings, no codes occurred initially at 56000 mile, has happened 10 or 12 times since then. very scary, im afraid to drive or tow now that dealer mentioned trailer brakes.

I was driving approximately 60mph pulling a trailer when the back tires locked up for approximately 2 seconds. This happened 3 times within 30 minutes. I've taken it to the GM repair shop. They have seen this happen to 3 or 4 vehicles. Due to not being able to replicate the fault it has been difficult to diagnose. They are going to replace the transmission valve body hoping that will take care of the issue. This is extremely dangerous to everyone on the road when this happens. There are many forums out there that I've read and have been close to deadly accidents involving cars, trucks, RV's, and semis as they've ran off the roads. This seems to be something worth looking into and ensuring GM puts out a recall for. In my case, I am going through an extended warrant for my 2020 3500 with 112,000 miles. The warranty company wants the GM technician to replicate the fault... which isn't possible without hooking up a trailer... also very dangerous which I refuse to do until the issue if resolved. In any case, I will have to hook up a trailer once the part is replaced... praying that it won't happen again.

Vehicle will not start due to known GM issues. This failure left my family stranded in cold dark unsafe area once already. If we were in the flow of traffic or had to leave an area immediately we would have been unable too. Known GM issue, engine fault code P12A6 fault code. Bulletin: PIP5719A discusses this issue. I am being told by the dealer there is a newer bulletin which advises ECM update. GM dealer is stating ECM software upgrade is required to resolve at owners expense. Owner is responsible for diagnostic fee in addition to repair costs. If the issue is not resolved vehicle may continue to experience starting failure and or other electrical problems. The night the vehicle left us stranded instrumentation was erratic and not reading properly on the instrument cluster. Very unsafe and GM should reach out to customers to inform them a software update is needed and it should not be at the expense to the consumer if the consumer is out of the bumper to bumper warranty.

The contact owns a 2020 GMC Sierra 3500. The contact stated that after stopping at a stop light, the light turned green and the contact depressed the accelerator pedal however, the vehicle failed to accelerate as intended. The contact drove a short distance and noticed that the failure was reoccurring. The contact drove the vehicle to a safe location and turned off the vehicle. The contact exited the vehicle and noticed that the exterior of the vehicle was covered with transmission fluid. The contact stated that the transmission fluid was also on the undercarriage of the vehicle and on the ground. The vehicle was towed to the dealer where it was diagnosed with a failed transmission fluid line. The contact was informed that the transmission fluid line needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and advised the contact to report the failure to the NHTSA Hotline. The failure mileage was approximately 28,000.

The contact owned a 2022 GMC Sierra. The contact stated that while her husband was driving at an undisclosed speed, the vehicle collided head-on with another vehicle that ran a red light. The air bags did not deploy. No warning lights were illuminated. A police report was filed. No injuries were reported, but the contact and her husband sought medical treatment for various bruises caused by the seat belt at a later date. The vehicle was not taken to the dealer or an independent mechanic but was instead towed to a tow yard. The vehicle was not repaired. instead deemed a total loss. The manufacturer was not notified of the failure. The failure mileage was 25,000.

While accelerating from about 45 - 60mph the truck made a loud bag and the rear tires locked up causing the vehicle to skid. This happened 4 times and nearly caused the cars behind me to crash.