Complaint volume
425 consumer-submitted complaints are matched to this model year. Treat the count as a research signal, then read the actual summaries for repeated symptoms.
Complaint records
2020 GMC Sierra Complaints
425 consumer-submitted complaints on record for the 2020 GMC Sierra, grouped by component category.
425 Total complaints
11 Crash reports
4 Fire reports
6 Injury reports
Complaint data reflects consumer-submitted reports. A complaint is not proof
of a defect, recall, or manufacturer fault. Enriched severity fields come
from official bulk records when the complaint can be matched by ODI number.
Buyer interpretation
How to use these complaints before buying
Complaint records are most useful when they turn into inspection points, seller questions, and comparison checks against nearby model years.
Pattern to inspect
The most common categories are engine, power train, electrical system. Use those categories as a test-drive checklist instead of judging the vehicle from the total count alone.
Severity flags
Enriched records include 11 crash reports, 4 fire reports, 6 injury reports, and 0 fatality reports. These fields come from complaint records and should be read in context.
Mileage clue
Mileage is available on 118 complaints, with an average reported failure mileage of 44,233 miles. Compare that with the mileage on the listing.
Questions to ask the seller
- Have you had any problems related to engine, power train, electrical system?
- Can I see recent maintenance and repair records?
- Has the vehicle ever been towed, involved in a crash, or repaired for the same issue twice?
- Can we also check the recall record for this 2020 GMC Sierra?
Used-car checklist
Use these complaints before the test drive.
Build a buyer checklist to turn these issues into questions and inspection points.
2020 GMC Sierra
Build buyer checklist Compare with other years Sends year, make, and model to pre-fill your checklist.
How severe are the 2020 GMC Sierra complaints?
11 Crash
4 Fire
6 Injury
0 Fatality
28 Towed
4 Medical attention
What are the most common 2020 GMC Sierra complaint categories?
ENGINE 125
POWER TRAIN 36
ELECTRICAL SYSTEM 21
POWER TRAIN,ENGINE 17
SERVICE BRAKES 16
STEERING 14
UNKNOWN OR OTHER 14
ENGINE AND ENGINE COOLING 9
SUSPENSION 9
ELECTRICAL SYSTEM,ENGINE 8
425 total complaints on record
Latest complaints
| Date | Component | Summary | Severity | Mileage |
|---|---|---|---|---|
| Feb 2024 | SERVICE BRAKES | Lost break, second time this month, showing break failed 40 mph max speed, abs light on, break light on, and 2 more light on the car with antislipiring or something like that, the another one no idea what it is | Crash: No Fire: No | Unknown |
| Feb 2024 | STRUCTURE | The back window leaks, I brought it in they told me it wasn't warranty so I paid to have it fixed. Still leaks. | Crash: No Fire: No | Unknown |
| Jan 2024 | POWER TRAIN,BACK OVER PREVENTION,FORWARD COLLISION AVOIDANCE | Lifters Failed in November 2023 and had repaired major engine damage including 4 cylinders, cam shaft, lifters, gaskets etc. After major repair work done. Truck is now doing same exact thing in January 2024. The dealership is stating they will not look at the vehicle unless i buy a new battery. I asked them to try a used battery to see if that makes a difference. And then if it is the battery i will replace. I was hung up on after the technician doug Pedersen stated ill have a supervisor call you back. | Crash: No Fire: No | Unknown |
| Jan 2024 | STEERING | While driving, the power steering (electronic) failed. Driver Info Center gave no waring until the system failed. After failure the DEC gave a warning to "Service Poser steering". | Crash: No Fire: No | Unknown |
| Jan 2024 | AIR BAGS | Driving on state highway at posted speed. A deer ran into the right front and side of vehicle. Side airbags deployed. When the right side airbag deployed, it burned a hole in my passengers winter coat that completely went through the right sleeve forearm and scorched the sweatshirt that she was wearing under the coat. Smoke was visibly apparent in the cab of the vehicle. We thought the truck was on fire , then finally determined it was the sleeve of here coat. | Crash: Yes Fire: Yes Towed | Unknown |
| Dec 2023 | UNKNOWN OR OTHER,VISIBILITY/WIPER | The rear window was leaking a substantial amount of water soaking the back seat. Had the service bulletin done, which did not work. Then under further inspection found cracks in the rear power window track. Dealer told me GM would not cover replacement because it was out of the 3 year warranty. Then was told it would cost me 1200 dollars to replace. GM should cover this because it will lead to black mold. | Crash: No Fire: No | Unknown |
| Nov 2023 | ENGINE | timing chain failure, timing chain components are available for inspection. Costly premature repair/failure. Could leave occupants stranded in unsafe environment which could lead to death. The vehicle has been diagnosed by the dealership and OEM manufacturer has been notified. There was a warning lamp. | Crash: No Fire: No | Unknown |
| Nov 2023 | SERVICE BRAKES,FORWARD COLLISION AVOIDANCE | ABS LIGHT LIMITED TO 43 MPH ESC system Steering assist reduced Service Trailer Brake System Engine light on | Crash: No Fire: No | Unknown |
| Sep 2023 | VISIBILITY/WIPER | The rear window on this vehicle is leaking water and has been for some time. It has become quite bad and is causing an odor and discoloration in the carpet. I could not find the cause of the problem until recently with the plastic cracking more. The vehicle has 41,000 miles and the dealer stated that is out of warranty and all repairs would be a cost to me. I researched this and have found it is a common fault this this vehicle. | Crash: No Fire: No | Unknown |
| Sep 2023 | STEERING,SUSPENSION,POWER TRAIN | The right side started clicking out of no where when I turn the steering wheel | Crash: No Fire: No | Unknown |
| Sep 2023 | ENGINE | I have a 202 GMC Sierra 1500 with a 3.0 Duramax with 95,000 miles. I have hade 2 glow plugs replaced under warranty and took in for a third glow plug. They stated that the there was a software update that could fix it, but I would have to pay for it. The vehicle has a 100,000 mile warranty and the software update is to fix a powertrain item that is covered under the 100,000 mile warranty. This is also an issue with bad software that disables the remote start. Not sure why I have to pay for this software upgrade to to a GM issue from day 1. | Crash: No Fire: No | Unknown |
| Aug 2023 | SERVICE BRAKES | The contact owns a 2020 GMC Sierra 1500. The contact stated while driving 60 MPH, the service brake, check engine, and ABS warning lights were illuminated. The contact took the vehicle to an independent mechanic to be diagnosed and it was determined that the passenger’s side rear caliper needed to be replaced. The vehicle was not repaired. The vehicle was taken to the local dealer to be diagnosed, and the contact was informed that the rear passenger’s side caliper needed to be replaced. The vehicle was not repaired due to the parts not being available. Upon investigation, the contact associated the failure with NHTSA Campaign Number: 20V116000 (Service Brakes, Hydraulic) however, the VIN was not included. The manufacturer had been informed of the failure. The failure mileage was approximately 69,000. | Crash: No Fire: No | 69,000 |
| Aug 2023 | FUEL/PROPULSION SYSTEM | Reference your GM/Chevy recall NHTSA [XXX] , I have a 2020 GMC truck with a failed Fuel Pump Control Module, same part/same part number used in the SUVs. Are you going to recall the trucks also. Lucky for me, mine failed as I pulled into my drive way. Had to have my truck towed to the dealership, 2 days later informed my FPCM was bad, and of course there are no replacement part available. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6) | Crash: No Fire: No | Unknown |
| Jul 2023 | SUSPENSION | The contact owns a 2020 GMC Sierra 1500. The contact stated while driving out of the driveway, the front passenger’s side wheel separated from the vehicle. The vehicle was towed to the dealer and the contact was informed that the upper control arm ball joint had fractured and that the front upper control arm needed to be replaced. The contact was informed that the vehicle was not included in NHTSA Campaign Number: 21V718000 (Suspension). The vehicle was not repaired. The manufacturer was not contacted. The failure mileage was 41,000. | Crash: No Fire: No | 41,000 |
| Jul 2023 | STEERING,ELECTRICAL SYSTEM | Electronic power steering stops working randomly which makes it nearly impossible to safely drive the vehicle. The strength needed to turn the vehicle is so great that the steering wheel elevation lock fails and the wheel slams to the lowest limit of travel. Problem started around 50,000 miles and was only a warning that went away as soon as I got in the truck again. However reappeared today and the steering went out this time. The GM dealer in Mexia Texas didn't know what was wrong, I am taking it to a dealer in Corsicana tomorrow. This is a known problem that GM has had in the past however my vehicle has no active recall to make my truck safe free of charge. This puts myself and other drivers at risk because there would be no way to rapidly maneuver the vehicle to avoid a colision. | Crash: No Fire: No | Unknown |
| Jul 2023 | FUEL/PROPULSION SYSTEM | My vehicle suddenly did not want to start without any warning. I drove my truck and everything was good until I turned it on with the remote and not even a minute after it shut off. I tried turning it back on and it only cranked but would not start. I had a mechanic diagnose it and their computer gave them fuel pump error code. They said it was the fuel pump control module and that they have been getting several GM trucks of the same year having that issue. My truck has less than 36,000 miles on it to have this issue and I have seen that GM has issues with their fuel pump components so I dont understand why they have not recalled them. This is a safety concern because these trucks auto shut off when stopped at red lights and it could randomly shut off and not turn back on leaving someone stranded in the middle of the road without any warning. | Crash: No Fire: No | Unknown |
| Jun 2023 | STEERING,SUSPENSION,POWER TRAIN | The truck has developed a shake that can be felt in the floor boards, seat, and steering wheel at highway speeds. It’s has spent several months at dealerships without being fixed. I have replaced tires, wheels, shocks, upper control arms, and the transfer case without success. | Crash: No Fire: No | Unknown |
| May 2023 | SERVICE BRAKES | We were hauling a trailer and driving approximately 65-70mph with cruise control enabled. The vehicle randomly disengaged cruise and the ABS telltale illuminated, lost brake functionality completely. Safety of my family and other vehicles around us was compromised! Downshifted to try and navigate the vehicle to the side of the road and the ESC warning text came on the screen. Was able to luckily stop vehicle by downshifting. Turned off ignition and then cycled back to run, brakes and all warnings were cleared. Started driving vehicle with flashers on the side of the road see what would happen and approximately ten miles later same thing happened but this time brake functionality was reduced significantly but not completely but still had to downshift to stop. Called GMC and was told this was not a recall even though vehicle brakes randomly stopped working. Told us they would do nothing since the vehicle was out of warranty 80k miles and warranty was 60k and also since no one was hurt. We were 1-2 hours from being in the Mountains driving and not sure we would be here today if this had happened in the Mountains! Dealership ordered a new master brake booster and ABS. When installed the part would not flash and GM engineering told them to replace the part a second time.They we’re told to keep flashing till it takes even though the second module was also bricked. Seems strange a new part would be broken as well and the master cylinder was resetting. Dealership states the vehicle is fixed but the safety of my family and others driving around me were in extreme danger when this happened. Do not feel safe driving this vehicle and not convinced this will not happen again. When we called GM they told us they are receiving many calls about this happening to AT4 vehicles but they have not issued a recall yet. Submitting this because vehicles should not randomly lose brake functionality and do not want others at risk or my family. | Crash: No Fire: No | Unknown |
| May 2023 | POWER TRAIN | Bearing in transmission failed at 75000 miles. Took to dealership and they said truck needs new transmission. Truck makes rattling noise in transmission pan. Dealer said that oil was full of metal shavings. Dealer also said that this was second truck in 2 weeks with same issue. No warning lights or check engine lights came on. Dealer advised that the transmission could fail and to park it until I can pay $6000 for transmission replacement. Dealer heard rattling and confirmed metal shavings. Transmission failure could result in traffic hazard or accident if transmission loses all drive ability. | Crash: No Fire: No | Unknown |
| May 2023 | AIR BAGS | The contact owned a 2020 GMC Sierra 1500. The contact stated that while he was stopped in traffic, he was rear-ended, which caused him to crash into the vehicle in front of him. The contact stated that smoke was seen coming from the air bag; however, the air bags failed to deploy. The contact had not sustained injuries. A police report was filed. The vehicle was towed to a salvage yard. The manufacturer was not made aware of the failure. The approximate failure mileage was 64,000. | Crash: Yes Fire: No Towed | 64,000 |
| Apr 2023 | ELECTRICAL SYSTEM | We are unsure what happened that caused the issue. One day the dashboard just started giving us error messages, 3 of them to be specific. One says check turn signals, another says check trailer brake light and another something else about brakes or turn signals. (We have to dismiss them all before anything on the dash is viewable). This issue is causing the blinkers to blink fast as though the blinker lights need replaced and it happens when turning right or left. The alerts continue to give us error messages every few minutes, even after we have dismissed them all. We had the truck at a shop trying to figure out the issue and his guys spent hours and replaced things he thought were causing the issue but nothing fixed it. He referred us to take it to the dealership service shop for troubleshooting so we took it to the GMC dealer where we bought the truck. GMC has already spent hours, maybe 5-7 hours at $150 per hour, trying to figure out what's wrong and have been unable to find anything wrong. The truck is still at the GMC dealership shop but I can get pictures of the errors when we get it back. | Crash: No Fire: No | Unknown |
| Apr 2023 | VISIBILITY/WIPER | My back window leaks and gm has said that the warranty is over by years not miles it is not covered | Crash: No Fire: No | Unknown |
| Apr 2023 | VISIBILITY/WIPER | My rear window leaks there is a bulletin on it Call GM says it is not responsible for the repair because it is over on the years but not the mileage it’s clear they know about the problem it’s in many pickups that gm manufacture here is the bulletin file:///var/mobile/Library/SMS/Attachments/97/07/3010617D-BBB0-4FB8-859B-4BA5E2BE3F3A/Ed%20blakeslees%20truck.png | Crash: No Fire: No | Unknown |
| Feb 2023 | ELECTRICAL SYSTEM,ENGINE | Camera always stays on even when i am driving camera still on my dashboard | Crash: No Fire: No | Unknown |
| Feb 2023 | ENGINE | Diesel exhaust fluid heater short circuits due to poor design. This issue occurs multiple times, including after being repaired. The failure limits the trucks capabilities until it is entirely unusable. | Crash: No Fire: No | Unknown |