Complaint volume
437 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
437 consumer-submitted complaints on record for the 2020 GMC Sierra, grouped by component category.
437 Total complaints
11 Crash reports
5 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, 5 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 121 complaints, with an average reported failure mileage of 45,188 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
5 Fire
6 Injury
0 Fatality
29 Towed
4 Medical attention
What are the most common 2020 GMC Sierra complaint categories?
ENGINE 130
POWER TRAIN 38
ELECTRICAL SYSTEM 22
POWER TRAIN,ENGINE 17
SERVICE BRAKES 16
STEERING 14
UNKNOWN OR OTHER 14
ENGINE AND ENGINE COOLING 10
SUSPENSION 9
ELECTRICAL SYSTEM,ENGINE 8
437 total complaints on record
Latest complaints
| Date | Component | Summary | Severity | Mileage |
|---|---|---|---|---|
| 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 | 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 | 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 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 |
| 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 |
| 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 |
| Jan 2023 | STEERING,ELECTRICAL SYSTEM,SERVICE BRAKES | I own a 2020 GMC Sierra 1500 4-Cyl, Turbo, 2.7 Liter with 20K miles and I owned the truck for almost 2 years. All of a sudden my vehicle started receiving multiple warning messages. While driving I stopped, and when traffic stopped in front of me the engine died all the lights were on warning messages on the dashboard started showing up. Electronic Stability Control, Antilock Braking System, ECM, reduced Engine Power, etc., and the brakes were hard to step on it and the steering wheel hard to turn,I took my foot off the brakes and pressed it again to start. It started but the check engine light was still on, this happened FOUR times already and THREE times while parked when I tried to start, after a few tries giving few minutes intervals, it will start with all the lights on and warning messages on the dashboard start showing up. Electronic Stability Control, Antilock Braking System, ECM, reduced Engine Power, etc., and the brakes were hard to step on it and the steering wheel hard to turn. | Crash: No Fire: No | Unknown |
| Jan 2023 | STEERING,ELECTRICAL SYSTEM,SERVICE BRAKES | Normal driving conditions vehicle decelerated and warning lights and notification appeared. Warning were ‘Service ECS’ and ‘Steering Assist is reduced Drive with care’. Shut off vehicle for 30 minutes and warnings were no longer present and vehicle drove normally. Happened again 24 hours later. Received email notifications from GMC to arrive within one day. This was a know recall of the previous model year. | Crash: No Fire: No | Unknown |
| Dec 2022 | VEHICLE SPEED CONTROL,SERVICE BRAKES | i was stopped at a red light and when the light turned green I accelerated and the vehicle shut off and then came back on. when the vehicle came on i had a service esc light and a system break failure warning telling me not to exceed 62mph. i made it back to my house driving with extreme caution. the breaks were very delayed while driving. | Crash: No Fire: No | Unknown |
| Dec 2022 | FUEL/PROPULSION SYSTEM | The fuel pump module failed according to the dealer at 34000 miles . Car stop while driving. Cranks but no start. After resting it for hours I was able to start. Drive couple of miles about 39000 miles it stops middle of driving and couldn’t start anymore but still cranks | Crash: Yes Fire: No Towed | Unknown |
| Nov 2022 | STEERING,SUSPENSION | Drivers side upper control arm failure. Threw truck into oncoming traffic. Dealership has inspected multiple times stating everything was good to go. Been complaining about a loud clunk to dealership for months | Crash: No Fire: No | Unknown |
| Nov 2022 | UNKNOWN OR OTHER | Once vehicle is put in park, the control panel comes and reads, “shift in park and radio and head lights stays on as well”. I exit the vehicle and it continues to display the mention above. I’ve restarted the vehicle and put it back in park still the “shift in park”, stays on. I exit the vehicle and monitored the vehicle for approximately 5 minutes and finally turned off. This never happened before, I’m afraid it may stay on one of these days and run the battery down. | Crash: No Fire: No | Unknown |
| Oct 2022 | POWER TRAIN | My 2020 Sierra SLT always hesitates or stutters upon take off only on the very first start of the day every day. It appears to be a transmission gear issue or perhaps air/fuel issue. I also have had several different issues with my infotainment system. It screen changes from one screen to another on its own occasionally and it also has a very loud pop when I turn off my iphone Xr from the trucks sound system as if it will crack my speakers. I have taken it in to two separate Cavendar GMC dealerships in San Antonio on 3 different occasions and they claim it does not do either. This cannot be the case as it does it for me every single day since I bought it from the showroom floor. They have said they have updated or reprogrammed both systems but I still have both issues. I am about to lose warranty coverage and I am afraid this will never be addressed. I am taking it in 1 last time. I will never buy another GM product! | Crash: No Fire: No | Unknown |
| Oct 2022 | SUSPENSION | I was taking my truck to have an oil change and tire rotation at the dealership. I have just traveled approximately 15 miles on the freeway, exited, and entered the parking lot of the dealership. I went over a speed bump at about 5-7mph and felt a clunk, with a grinding sound and the car pulled to the right. I got out of the truck and found the front passenger wheel was hanging off with only the lower connections attaching it to the frame. (Control arm maybe?). The service department worker was right there when it happened. He told me they have been having issues with the leveling kits on 2020 GMC sierras causing this issue, especially on the right side. He said that this was not the first that he had seen. Two other people at the dealership mentioned the same thing. I was never notified of the potential failure and possible catastrophic consequences. I contacted GMC who's "Product Allegation" department told me they could not investigate because the truck was repaired at the dealership. They didn't even review the photos I had sent them. | Crash: No Fire: No Towed | Unknown |
| Sep 2022 | FUEL/PROPULSION SYSTEM | The vehicle shut off while driving. It turns over fine but will not crank. Later cranks but again will shut off and not start. This could get me killed on the interstate. It is pulling trouble code P129F fuel pump power control module. This is a 2020 GMC Sierra AT4 with a 6.2 motor with 80,000 miles on it. | Crash: No Fire: No | Unknown |
| Sep 2022 | POWER TRAIN | Consistent issues with my truck. It is a 2020 GMC Sierra 1500 vin: [XXX]. In April 2022, my truck started to exhibit concerning issues. I was worried about driving home from work and called the dealership I bought the truck at. They recommended that I take it to the the service center in Frankfort, KY where I work. I drove the truck directly to Neil Huffman GMC. They declared the truck unsafe for me to drive. They set up rental car for me to use and I left the truck at the service center. They initially said it was the torque converter. Over the course of two months they kept finding more issues. Repairs were completed at Neil Huffman GMC service center located in Frankfort, KY. My truck still has the following issues.. 1. Ringing sound 2. Grinding or clunking noises 3. Loud noise when I press the gas pedal 4. Delayed shifting and hard shifting problem I drive a hour back and forth to work everyday and don’t want the truck to have issues on the interstate. Driving with a bad torque converter is unsafe since it causes sudden stoppages and significant speed fluctuations. Worn or slipping transmissions have many warning signs. A damaged transmission creates a dangerous situation for me and for other drivers. I had an appointment at Adams GMC in Richmond, KY on September 1st. They said they couldn’t hear anything and no services were conducted. Neil Huffman GMC service department said they replaced basically the entire transmission. I don’t understand why there would be issues still. [XXX] INFORMATION Redacted PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6). | Crash: No Fire: No | Unknown |
| Sep 2022 | SERVICE BRAKES | Brake pad monitoring system alert came on driver information center warning screen. Brought to local dealer who told me I needed new brake pads. There is a current safety bulletin on the NHTSA.GOV website for the 2019 model year GMC Sierra, as well as the 2019 Cadillac CT6, but not he 2020 model year. The week prior my driver information center reported front brakes in the high 80's and the rears in the low 90's in terms of percentage of brake life remaining. How can the system go from being safe to being unsafe in a week (and less than 200 miles)? At this point I don't know if my vehicle has a safety problem with my brakes or if there is a sensor and programming issue as described in recall N192264451. I have no observable issues while braking - no pulsing, noise, chattering - that would indicate any brake problems. My only inclination is the alert on the driver information center. Both local dealer and GM customer service are telling me to perform service and pay out of my pocket. This seems inconsistent based on the above recall. | Crash: No Fire: No | Unknown |
| Sep 2022 | UNKNOWN OR OTHER | Rear window (the one that faces straight back towards bed of truck) is leaking… Haven’t taken it in to dealership for repair because I’ve exceeded mileage so truck is no longer under warranty… Not sure how long it’s been leaking but I’ve recently noticed that water stains (runs) on the inside of this window after rains, washes, etc… | Crash: No Fire: No | Unknown |
| Aug 2022 | SUSPENSION | With out any warning my right wheel had broken when I tried to drive from my dive way to work. Looks like Excessive wear to the front-upper control arm ball joints resulted in ball joint failure and wheel separation. Reported to a dealer. Waiting for the appointment to do full investigation. Separation of a front wheel while the vehicle is in motion increases the risk of a crash. I drive in city and highway roads, nothing rough. Very high risk for lots of lives!!!!!! People can die!!! Need immediate attention!!!! Please see https://www.consumeraffairs.com/recalls/fox-factory-recalls-gmc-sierra-1500s-and-chevrolet-silverado-1500s-101321.html Concern DATED and published on 10/13/2021 Why nothing has been done to warn the owners? I smell lots of lawsuits. | Crash: No Fire: No | Unknown |