GMC Sierra Complaints (2020)
626 consumer complaints on file.
- #11449659January 31, 2022ELECTRICAL SYSTEM, ENGINE
I have a lifters problem that the dealership takes more that three weeks to fixed without a loaner car, then i have electrical problems where the truck doesn't start at all without any warning and that's it's dangerous, never now where its going happen
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11448544January 23, 2022ELECTRICAL SYSTEM, ENGINE, SERVICE BRAKES
Truck has had multiple issues related to the electrical system and truck modules. It is my opinion that these are all related to voltage issues or module problems. i have had multiple infotainment issues with delays loading, freezing up etc. dealer has ran updates and checks with nothing found. In October around $35k miles the truck Radio would not work if i used the push button start. if i shut the truck off opened the door and let everything reset i could push the start button in the truck and the radio would work majority of the time. The next day i went out to a completely dead truck. I talked to my service department at the local dealer and they said i would need to bring it in but suggested i disconnect the batteries and recharge the batteries. after doing so everything started working correctly. it fixed my radio problem and never went dead again. since then i have experienced popping noises through the speakers when playing music occasionally. over the last few weeks i noticed the engine does not attempt to increase cold idle speed until i press the brake to put it in gear. January 22nd i hit the autostart button and it did not work. i started the truck and it had CEL, Traction control, park brake and wrench, lights on with service emissions, and power reduced messages displayed. Truck is running odd. codes present are (ENGINE GMLAN)P0118 - engine coolant temp circuit high voltage, (BRAKES GMLAN_ABS) U0401- invalid data from engine control module, P0562- system voltage low, (HVAC CONTROLS GMLAN_HVAC) B1325 - . control module power circuit. Truck is starting and charging fine. No connection issues at batteries. There are many TSB's and many complaints regarding similar issues. common brake and emissions faults with minor differences. Module failures, communication faults, and or electrical faults are likely causing all of these similar issues. they need to be categorized as the same failure group which will show GM has a bigger issue.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11444113December 17, 2021FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING
Was driving truck down driveway at about 5km per hour and the parking brake automatically engage bringing the vehicle to a sudden and unexpected hard stop. Brought to dealership, then said they cannot duplicate the problem and therefore there is no action to be taken.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11444126December 17, 2021VEHICLE SPEED CONTROL
While driving Truck was setting Cruise Control at approx 100km/hr. The cruise would set but at approx 70km/hr. Tried to set multiple time throughout the trip but no change. Recorded video and sent to dealer. They brought truck in to check it out, but said that since they can't duplicate the problem they cannot diagnose it. This has happened multiple times and have recorded video each time. Again dealer said they can't do anything unless they see it themselves.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11442892December 6, 2021ENGINE
The contact owns a 2020 GMC Sierra 1500. The contact stated that shortly after refueling while driving under 15 MPH, the check engine and service emissions warning light illuminated. The contact stated that an unknown reset was performed related to TSB: 10173675 (Engine). The vehicle was not yet fully repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 46,000.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11441449November 23, 2021ENGINE
The contact's father owns a 2020 GMC Sierra Denali 3500. The contact stated that while his father was driving at an undisclosed speed, the check engine warning light illuminated. The vehicle was taken to the dealer and diagnosed with a cylinder #1 misfire. The vehicle was repaired; however, the failure recurred. The vehicle was then taken to Wackerli Auto Center (1363 N Holmes Ave, Idaho Falls, ID 83401) on numerous occasions and diagnosed with a faulty sensor. The dealer replaced the sensor; however, the failure recurred. The vehicle was not repaired and remained at the dealer. The manufacturer was made aware of the failure. The failure mileage was approximately 20,000. The VIN was unavailable.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11441231November 21, 2021SUSPENSION
At 8,000 miles I started hearing a clunking noise in my truck when I hit a small bump or back up out of drive way. Brought in and GMC stated it was normal and no issues at walser buick gmc of Roseville. Brought I back again because it was getting worse and could hear it every time I slowed down and accelerated. Then stated they need to order spacer bushings at walser of Bloomington. Then went back for 3rd time and installed them at Bloomington.After 600miles noise was back and is getting worse again. I called Walser of Bloomington again and said I need to drive it for 1000 miles to break in spacers. So now we have 11,000 miles on truck with same noise again and its going back again because needs to get fixed. GMC is just asking for something to happen. Also when this first happened at 8,482miles I was on 35w and the rear end started wobbling and gave me a small death wobble but I slowed down to control it. That’s when I brought it in and it could of hurt or killed somone.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11440826November 17, 2021ELECTRICAL SYSTEM
Infotainment system AND center instrument cluster went completely black - six times over the course of one month. I took the truck to Alan Webb Chevrolet in Vancouver Washington. Their service technician was aware of infotainment system “Black Screen of Death - BSD” problems due to previous repair work on several different GM models. However, on the way to their Service Department to get this fixed, I rolled down the driver’s side window about 6 inches to get some fresh air and rolled it back up. Out of nowhere the Infotainment system AND the center instrument cluster came back to life. No rhyme, no reason and both stayed on (illuminated). Their Service Technician could NOT recreate the BSD. They had my truck for more than one week AND said they were working with GM engineers to resolve this issue. GM case number SR 9-7065134382. I’m driving and towing my 5th wheel blind without a remedy for this electrical issue.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11440605November 16, 2021SERVICE BRAKES
Brakes have been squealing since 4000 mile mark. Dealer states it’s normal.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11438339October 27, 2021TIRES
The contact owns a 2020 GMC Sierra 1500 equipped with Goodyear Tires, Tire line: Wrangler AT/S, Tire Size: LT275/65/R20, DOT Number: PJOTJB1V. The contact stated while driving 65 MPH, there was a slight wobble and then an impact was felt when the rear passenger’s side tire tread separated and damaged the rear fender and bumper. The contact pulled over and had assistance replacing the rear passenger’s side tire with the spare tire. The dealer was made aware of the failure and was in possession of the failed tire. The manufacturer was not made aware of the failure. The failure mileage was unknown.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11435051September 30, 2021ELECTRICAL SYSTEM, SERVICE BRAKES, FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING
Own a 2020 GMC Sierra AT4 with 13K miles and I owned the truck for 1 year. All of a sudden my vehicle started receiving multiple warning messages. Electronic Stability Control, Antilock Braking System, ECM, reduced Engine Power, etc. I see there was a recall for 2019 GMC Sierra's for the same issues. Why isn't 2020 GMC Sierra's not also part of that recall ? It is ridiculous that a brand new truck has these types of serious issues affecting so many vehicles. Why is GMC allowed to continue to sell later model trucks after the 2019 recall with the exact same ESC and Anti-lock Braking system problems ?
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11434588September 27, 2021SERVICE BRAKES, ELECTRICAL SYSTEM, ENGINE
Two times while on the freeway the service parking brake and engine lights came on and starting braking. Could not drive over 20 mile an hour. Both times taking to dealer the lights where not on and they could not find anything wrong. I even have video of it happening.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11434431September 26, 2021SUSPENSION
The leaf springs appear to have failed. The vehicle is available for inspection. If the leaf spring brakes, control of the vehicle could quickly become an issue. On 9/24/21 I brought my truck into the local GMC dealer for inspection. The service technician indicated the leaf springs show “possible overloading” and recommended air bags to level the truck. The heaviest load for this truck has been a 4,000 lb. fiberglass fishing boat. At this time, no one else has inspected the truck. The truck, when empty, sits lower in the rear than in the front. If a small trailer is attached, it becomes even worse. Oncoming cars flash their headlights thinking mine are on high beam, which they are not.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11432679September 12, 2021SUSPENSION, POWER TRAIN, SERVICE BRAKES
I purchased the 2020 Sierra 1500 because the label on the truck frame states that it can tow 9300lbs. Subsequently, in April 2021, I purchased a 34' Travel Trailer with a max capacity of 8995lbs. In August, I received a notice from GMC that they overstated the towing capacity by 500lbs. The new towing capacity is 8800lbs. GMC's response to my request for a refund was that they were not going to help me. Their solution is that I can be provided a new sticker by the dealer upon request. This does not resolve my issue, nor the issue of other Sierra owners who purchased this vehicle because of its stated towing capacity. In doing research, it appears that in model year 2014, GMC faced a class action lawsuit for misrepresenting their capabilities. I believe that this malpractice is a safety concern for me and many others. Attached is the towing label on the frame and the letter from GM.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11431842September 6, 2021ELECTRICAL SYSTEM
Bought 9-4-2020. On 9-4-2021 went start vehicle and no electrical power, battery dead. Will not hold charge to start. Brand new purchased at Morgan GMC in Shreveport Louisiana
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11431592September 3, 2021SUSPENSION
I was driving my 2020 GMC Sierra AT4 at about 15mph on a 2 way city street slowing for a traffic light when my vehicle started to shake violently...at first thinking it was a flat, but the shaking was much different. As I was slowing in anticipation of the light, now at about 5mph, my truck suddenly dropped and stopped. This would have been catastrophic at freeway speeds! I immediately thought maybe someone had tried to steal the wheel overnight as I knew now it was not simply a flat, but knew I had wheels locks and thought that unlikely....this was while I was exiting my now parked truck. I knew the problem was on the front passenger side, and was shocked as I rounded the vehicle from the front only to find the entire front wheel assembly folded flat under my truck. The entire brake assembly was still intact, but the front drive shaft was pulled out, as well as the upper and lower ball joints. The brake hose became severed in this incident.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11431270August 31, 2021ELECTRICAL SYSTEM, VEHICLE SPEED CONTROL, FORWARD COLLISION AVOIDANCE: ADAPTIVE CRUISE CONTROL
Issue 1: Front left sensor(s), after a rain, car wash and now after an oil change, continuously vibrates the drivers seat and the red light warning stays lite indicating that an obstacle is located near the left front of the truck. This has happened on several occasions and after a time both indicator stop. Issue 2: When traveling on a freeway, twice now, the cruise control suddenly disengaged or decreased mileage, as if it had detected a vehicle in front of us. There was no vehicle within a quarter mile of us front or back, nor any vehicles on the side. No debris in the road either. Usually when the adaptive cruise is set and detects something in front the icons on the dash turn orange and starts to flash. That didn't happen, rather the cruise icon changed to blue in color and the truck slowed. This I would consider a safety risk. Both instances (December 2020 and April 2021) have been reported to a dealership and noted in a file. When the customer care person attempted to get malfunction codes, nothing appeared to be wrong with the vehicle.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11428904August 12, 2021ENGINE
Repeated issues with exhaust and emissions components.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11428150August 7, 2021ENGINE
Found improperly installed rear seals. The truck leaked oil and had to be towed to gmc dealership in Monahans Texas to be repaired. 1 month later the truck leaked oil again.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11425566July 19, 2021ENGINE
Rear main oil seal failure causing truck to lose all oil, leaking all over truck, trail leading to drive and garage; possibility of engine seizing up while driving causing an accident, confirmed by dealer, covered by warrenty, is a known issue, no warning lights, messages, or other symptoms of problem, NHSTA has issued a bulletin for this problem
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0