GMC Sierra Complaints (2020)
626 consumer complaints on file.
- #11646652March 6, 2025ELECTRICAL SYSTEM
Had GMC (Leominster, MA), perform the safety recall for the transmission on my Sierra. This is the one for the rear wheel lockup that requires a software update. My battery was completely dead after the vehicle sat for a week. No accessori s plugged in, and it's a 6 month old battery Battery tested fine and is charging now, but it appears the CPU never fully powered down after the software update, resulting in needing multiple jump starts and 3+ hours of run time to charge the battery enough to turn over on its own. I can see this being a safety issue in relation to the Auto-start, because when it is being used, the battery is needed to restart the engine. This could result in a stall at an intersection, and if drivers are not alert, may collide with a stalled vehicle.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11646739March 6, 2025POWER TRAIN, UNKNOWN OR OTHER
My truck had been sitting idling for about 20 minutes on a job site on flat level ground. I turn around for whatever reason and my truck is driving forward with on one in it but my dog. The truck ran into an out rigger on my crane. I had 3 of my employees there that witnessed this happen. I got into my truck and the shifter was in drive. Somehow my dog was able to shift my truck into drive from park while it was sitting idle. I have 3 eye witnesses as well as pictures of the incident. I have pictures but was no able to upload them to they portal.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11646779March 6, 2025STRUCTURE:FRAME AND MEMBERS:UNDERBODY SHIELDS, PARKING BRAKE, ENGINE
The contact owns a 2020 GMC Sierra 1500. The contact stated while driving at an undisclosed speed, the parking brake was independently activated. In addition, the contact stated that the vehicle had an oil leak from the oil pan. The contact stated that the oil needed to be added every two days. The contact stated that the alert system warning light was illuminated. The vehicle was taken to the dealer; however, the failure was not duplicated. The contact was informed that the failure could not be duplicated, because no active codes were retrieved. In addition, the contact stated that the frame had corrosion. The vehicle was taken to the dealer for corrosion failure, however, the contact stated that the previous dealer had failed to help. The dealer confirmed the corrosion; however, the vehicle was not repaired. The manufacturer was made aware of the failure but provided no assistance. The contact was advised to contact the NHTSA Hotline to report the failure. The failure mileage was approximately 10,000.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11646537March 5, 2025POWER TRAIN
The contact owns a 2020 GMC Sierra 3500. The contact received notification of NHTSA Campaign Number: 24V797000 (Power Train); however, the part to do the recall repair was not yet available. The contact was concerned about the remedy repair not being adequate to repair the vehicle. The local dealer was contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The contact had not experienced a failure. Parts distribution disconnect.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11646611March 5, 2025ENGINE, POWER TRAIN
Lifters failed and cam shaft was busted. Standard issues with 6.2L engines. Was traveling down highway and vehicles was shaking violently. Inspection report available. Has been inspected by GM service center. No symptoms or warnings prior to failure.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11646185March 4, 2025POWER TRAIN
The contact owns a 2020 GMC Sierra 2500. The contact stated while driving 30 MPH, the engine revved while the vehicle lost motive power in the middle of the road. The contact was unable to pull over to the side of the road. The vehicle was restarted but was undrivable. An unknown warning light was illuminated. The contact stated that while the vehicle was being towed, there was a significant amount of fluid leaking onto the ground. The vehicle was towed to Ryan's Repair, where it was diagnosed with a fractured transmission cooler line. The vehicle was not repaired. The mechanic related the failure to an unknown recall. The dealer was not notified of the failure. The manufacturer was notified of the failure, but no assistance was provided because the VIN was not included in the TSB. The failure mileage was approximately 112,000.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11645862March 2, 2025ELECTRICAL SYSTEM, BACK OVER PREVENTION: WARNINGS, STRUCTURE:BODY
Vehicle was parked in a school parking lot. Rear Trailer Harness and modules in back short circuited causing an electrical fire that expanded to the driver’s taillight rear bumper, and bed of truck.
- Crash:
- No
- Fire:
- Yes
- Injuries:
- 0
- Deaths:
- 0
- #11645490February 28, 2025FUEL/PROPULSION SYSTEM
I was towing my 44'camper entering the highway and during excellration there was a loud bang and the truck shuddered no lights on the dash. Pulled over and did a visual check of the vehicle and did not see anything out of ordinary. Continued on our journey and during the the week noticed clunking noise when shifting into park and into drive with no camper. We shortened our trip and returned home with no futher incidents. Received recall letter from GM in December, called the dealer and was told Gm has not released my VIN number yet. Called twice in January 2025 and the software was done on February 20, 2025. Truck seems to run as it should. I use the truck for business and to tow my camper. The software is only a patch. My fear is I'm out traveling with my 44' camper and the truck goes into limp mode limiting to fifth gear. Then I have to get the truck towed home and the camper. I travel with 3 dogs too. GM has known about this issue and has failed to fix the problem leaving me and my family at risk of a serious accident. I can not work without my truck and GM does not care about me or my family. I have several camping trips scheduled for this year and I'm considering canceling them because I don't feel comfortable with the software update.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11645276February 27, 2025POWER TRAIN
The contact owns a 2020 GMC Sierra 2500. The contact received notification of NHTSA Campaign Number: 24V797000 (POWER TRAIN); however, the part to do the recall repair was not yet available. The local dealer was contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The contact had not experienced a failure. Parts distribution disconnect.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11644738February 25, 2025STRUCTURE:BODY
While towing my dump trailer early in the morning for about 20 minutes I noticed sudden hard up shifting and down shifting in some gears on flat surface roads. I then proceeded to approach an incline hill about a 5% grade and then, what I've recently learned, my transmission locked up and released for a split second. The roads were slick so it didn't seem too harsh, I continued with no incident for another 40 miles and then it happened again while pulling up a 7% grade in a left hand sharp turn at 40 mph. The truck fish tailed and jack knifed my trailer on the left rear side of my truck and the front left side of the trailer. I was on a one lane road and had to continue until I reached my detitanation, I slowed and maintained a speed of 45 in order to prevent it from happening again but it did it 5 more times before reaching my destination. I'm currently scheduled to have the transmission checked on 02/27/2025 at Peterson's Chevrolet Nampa Idaho. In the meantime, I have no means of using any of my trailers.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11644408February 23, 2025ELECTRICAL SYSTEM
While driving on interstate transmission would “lock up” momentarily creating drastic drop in speed and unable to shift gears and accelerate. “D” would start flashing in dash board. Dealership said this is unrelated to current recall about rear wheels locking up from valve body failure and instead this is an electrical issue. Dealership also stated this is the 2nd truck in a week they have had come in with this issue. Almost caused accident on interstate with my family and I as a result of sudden drop in speed and unable to accelerate with multiple cars behind us.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11643561February 18, 2025STRUCTURE:BODY
Tailgate opened on highway with cargo in bed. Also tailgate opens randomly when parked. This has happened many times, creating very dangerous and unexpected situations Numerous contacts to the manufacturer have been unsuccessful in getting the hazard placed on recall. Numerous incidents. Keeps happening
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11643258February 17, 2025ENGINE
My engine has had continual random piston misfire issues, I have changed the spark plugs, fuel injectors, and cat converter. The vehicle has "dynamic fuel management" (DFM) where four of the cylinders turn off when the load on the engine is low and turn back on when the load is high. A mechanic reviewed the vehicle and determined that all eight cylinders are turning off while driving due to the DFM. When it misfires there is momentary loss of power that potentially puts others at risk. A dealership performed a repair per a Bulletin but the issue was not fixed. The mechanic indicated this is a software issue with the computer update per the Bulletin. I have installed a DFM disabler to prevent DFM from working, don't have misfires, but this is an engineering issue that GM hasn't/won't address.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11642682February 14, 2025STEERING
I went to start my truck after going into the store and the Service Power Steering ESC warning came on and I had no power steering. This is a very dangerous situation without power steering in the vehicle and someone is bound to get seriously injured if this happens while they are driving. I have read numerous threads on this same issue and it does not look like GM has taken this into accounty by recalling all these vehicles with this same exact issue. While most complain that when they take it to the dealership, they cant find any error codes, or when the replace the modules it starts creating more issues with other electronics. GM needs to take care of this issue with the power steering module so the safety of their drivers is not compromised.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11642855February 14, 2025STEERING
The ESC comes on and loss of power steering
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11642503February 13, 2025ENGINE
The engine failed. There was no warning. The truck literally just cut off in the middle of the road. I never saw any lights or there was no symptoms to lead up to this incident.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11642616February 13, 2025POWER TRAIN
The contact owns a 2020 GMC Sierra 2500. The contact received notification of NHTSA Campaign Number: 24V797000 (POWER TRAIN); however, the part to do the recall repair was not yet available. The local dealer was contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacture was made aware of the issue. The contact had not experienced a failure. Parts distribution disconnect.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11642238February 12, 2025ENGINE, TRACTION CONTROL SYSTEM
The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving 65 MPH, the check engine and the traction control warning lights illuminated. The contact stated that a dealer was contacted. The vehicle was taken to a dealer where it was diagnosed and determined that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure and informed the contact that he would receive a callback. The approximate failure mileage was 87,000.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11641886February 11, 2025ENGINE
At 125,000 miles, the CEL came on and the code is P0016, which is for the timing chain has stretched and jumped a tooth. The engine was new in 2019 and in 2021, they redesigned the timing chains due to early failure. The oil pump belt is listed for inspection/replacement at 150,000 miles, but the timing chain does not give any interval for replacement and should easily outlast the oil pump belt to at least 250,000 miles. GM knows that there is a timing chain issue with the 3.0 Duramax LM2 engine and it is costing owners between, $7,800 and $10,000 to repair.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11641672February 10, 2025POWER TRAIN
GM 10L80 Speed Transmission Pump Idler Gear Failure causing erratic shifting, lurching, or being stuck in gear. Dealer confirmed and recommended to replace the transmission. Transmission was replaced out of pocket in December. The issue is widespread on youtube.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0