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 |
|---|---|---|---|---|
| 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 | 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 | 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 | 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 |
| Aug 2022 | UNKNOWN OR OTHER,ENGINE | Vehicle engine went out on truck. | Crash: No Fire: No | Unknown |
| Jul 2022 | STEERING | I started my truck like normal and my service power steering light drive with care message came on and then Service ESC and the traction control light. My power steering was completely gone. I researched and found that 2020-21 GMC SUVs were recalled due to the same issue. My GMC truck is doing the same thing. I barely made it home from the store not having power steering is extremely dangerous, I still have no power steering. I just purchased this truck from CarMax last month. | Crash: No Fire: No | Unknown |
| Jul 2022 | STEERING,VEHICLE SPEED CONTROL,SERVICE BRAKES | The truck stated to have the check engine light on, by the time that happened the brakes were hard to step on it and the steering wheel hard to turn, I had been asking to GMC superior of Siloam springs to check the truck because, got scared while I couldn't make stop the truck while on traffic, but they don't had open appointments for that day or the other following days, so a week after they got one and I missed because my work, I set another one at GMC on Springdale but they want me to charge me whenever the truck has an extended warranty, so I told them to leave it like that so finally got another appointment at Siloam springs location but while driving down there the same thing happened all the light on warning messages on the dash board start showing up and the brakes were hard to step on it and the steering wheel hard to turn, I got told them what was happening, about and how exactly happened. That day after 30 minutes I got a call saying that it was fixed I still asked if they were sure he said yes, the next day I almost crashed with a neighbor at my work place because I couldn't stop the truck, so today I took back the truck and the guy at the desk told me that they may just erase the codes and don't really checked what was wrong, I'm just filling this report because even if I got full coverage on that truck, I'm not gonna be responsible if I'm involved in an accident. | Crash: No Fire: No | Unknown |
| Jun 2022 | VEHICLE SPEED CONTROL | I investigated and Unintended Acceleration crash that occurred on 8-9-2021. The vehicle had just left a body shop where it had repairs to the left front of the vehicle near the ECM. The driver reported the vehicle would not slow down. He face timed a witness and showed her his foot was on the brake and not the accelerator pedal collaborating his statement. The 2020 GMC accelerated to 93 miles per hour crashing into the back of a Cadillac Escalade. Upon impact the fuel tank of the Cadillac exploded igniting both vehicles on fire and burning a fed-x truck that was folded in half from the sever impact. The EDR report stated the brakes were applied fully for a full 5 seconds prior to the crash while the vehicle was still accelerating. The accelerator was reading a constant 57% during the lead up to the crash and the brake rotors showed heat related glazing from excessive braking. The engine torque was also at 1023NM leading up to impact collaborating Unintended Acceleration further. Based on the evidence gathered my opinion is there was a short in the components in the left front of the vehicle most likely the ECM harness that caused the crash. It is unknown if the damage was caused by the previous crash, the body repairs or a manufacture defect at this time. The radiator had also just been replaced so moisture could have contributed to the malfunction. If moisture shorts APP-1 to APP-2 the safety systems can fail to detect a single fault because it causes redundant faults | Crash: Yes Fire: Yes Injuries: 7 Towed Medical attention | Unknown |
| May 2022 | SERVICE BRAKES | This vehicle was involved in a fatal crash when it rear ended an SUV stopped at a red traffic light. The driver alleges mechanical failure of the brakes. Police performed a vehicle download which captured 5 seconds of pre-accident data. The download shows the accelerator pedal was fixed at exactly 57% the entire 5 seconds pre-crash while the driver simultaneously applies the brakes the entire 5 seconds. A city bus captured the crash on a dash camera. Despite the driver desperately applying the brakes, the vehicle's speed continued to increase and the driver was unable to avoid the collision, and burst into flames upon impact. The vehicle mileage is less than 2,500. | Crash: Yes Fire: Yes Injuries: 2 Towed Medical attention | Unknown |
| Apr 2022 | ENGINE | A VERY STRONG "AMMONIA" ODOR COMES INTO THE CABIN. THIS HAPPENS WHEN THE DEF FLUID IS GOING INTO THE EXHAUST SYSTEM FOR THE REGEN PROCESS. THE ODOR MAKES PEOPLE INSIDE NAUSEOUS AND DIZZY. MUST OPEN WIDOWS OR STOP AND GET OUT OF THE VEHICLE. OUR GMC DEALER CAN FIND NO CODES OR PROBLEMS WITH THE EXHAUST SYSTEM. WE HAVE ALSO NOTICED THAT THE DEF FLUID HAS GONE DOWN VERY QUICKLY SOMETIMES DURING THIS EVENT. IT IS RANDOM. SOME DAYS NOTHING, OTHER TRIPS 3 AND FOUR TIMES THAT THE ODOR OCCURS. LOOKING ONLINE- THERE HAVE BEEN MANY POST ABOUT THIS PROBLEM. | Crash: No Fire: No | Unknown |
| Mar 2022 | POWER TRAIN | The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle shuddered. The vehicle was taken to the dealer however, the mechanic could not duplicate the failure. The vehicle was then taken to Gilland Chevrolet GMC (3071 N US Hwy 231, Ozark, AL 36360) where the contact was informed that the vehicle already had new transmission fluid filled in the transmission. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 42,000. | Crash: No Fire: No | 42,000 |
| Mar 2022 | STEERING,ELECTRICAL SYSTEM,VISIBILITY | The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving in the snow, the tire pressure and power steering warning lights illuminated. The vehicle was not diagnosed or repaired. The vehicle was taken to a dealer where it was confirmed that there were no recall or warranties that would cover the repairs for the warning lights. The failure mileage was 140,000. | Crash: No Fire: No | 140,000 |
| Feb 2022 | STEERING | Steering locked up after normal use at lunch. After sitting, traction control light then on and wheel would not turn after work. Did a computer reboot and steering released. Results still pending, she is not home yet. | Crash: No Fire: No | Unknown |
| Feb 2022 | AIR BAGS | I receive at random times the warning in the DIC (driver information center) on the dash of my car together with an air bag warning light. I have had this happen sometimes frequently and sometimes not for a thousand miles. I have taken it in at least 8 times, some parts were replaced in seat belt, but it continues to show up. The problem is it now doesn't leave a code but my local dealer said if it ever came up when I could get it to them to bring it in and leave it running. that happened and I brought it in the ran a computer check and got a code. I had to leave for Florida 2 days later, so they said bring it in to a dealer in Florida, give them the code, which I did, they checked it but said they will not replace parts without an active computer code. Problem started around 11K miles; I have 32K miles, and dealer wont replace parts unless they know they are bad. | Crash: No Fire: No | Unknown |
| Jan 2022 | ELECTRICAL 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 | Unknown |
| Jan 2022 | SUSPENSION | A vehicle with 45,000 Miles had ball joint shear from the upper control arm of front left suspension resulting in wheel separation from the ball joint. Similar situations happening with similar 2020 GMC Sierra's (Note: NHTSA Recall Notice, No. 21V718). Could have resulted in a vehicular crash if speed had been increased prior to separation. | Crash: No Fire: No | Unknown |