Complaint volume
487 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
2021 GMC Sierra Complaints
487 consumer-submitted complaints on record for the 2021 GMC Sierra, grouped by component category.
487 Total complaints
5 Crash reports
6 Fire reports
2 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, engine and engine cooling. Use those categories as a test-drive checklist instead of judging the vehicle from the total count alone.
Severity flags
Enriched records include 5 crash reports, 6 fire reports, 2 injury reports, and 0 fatality reports. These fields come from complaint records and should be read in context.
Mileage clue
Mileage is available on 104 complaints, with an average reported failure mileage of 51,093 miles. Compare that with the mileage on the listing.
Questions to ask the seller
- Have you had any problems related to engine, power train, engine and engine cooling?
- 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 2021 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.
2021 GMC Sierra
Build buyer checklist Compare with other years Sends year, make, and model to pre-fill your checklist.
How severe are the 2021 GMC Sierra complaints?
5 Crash
6 Fire
2 Injury
0 Fatality
30 Towed
3 Medical attention
What are the most common 2021 GMC Sierra complaint categories?
ENGINE 156
POWER TRAIN 59
ENGINE AND ENGINE COOLING 37
POWER TRAIN,ENGINE 29
ELECTRICAL SYSTEM 26
UNKNOWN OR OTHER 14
STEERING 13
UNKNOWN OR OTHER,ENGINE 12
ELECTRICAL SYSTEM,ENGINE 9
SERVICE BRAKES 9
487 total complaints on record
Latest complaints
| Date | Component | Summary | Severity | Mileage |
|---|---|---|---|---|
| Jun 2023 | ELECTRICAL SYSTEM | My son got into the car to drive it and saw a black screen with a message that states “update failed, see dealer” and had multiple languages. Since that date, he has no GPS or backup cam, which he relies on as a new driver. Nothing at all in the info system works. | Crash: No Fire: No | Unknown |
| Jun 2023 | UNKNOWN OR OTHER | I have HD surround vision cameras. I was parallel parking very slowly. The back end of my truck was in so I was watching the camera to see the front right of my truck and the back left of the other vehicle. I could see both vehicles including the road between them. There was space between the vehicles on the camera when I hit the other car. I called Sewell Buick Gmc and explained the camera might need calibrating. They sent a loaner car and picked mine up, When the driver arrived I explained the situation. It surprised his so I said get in my truck and put in reverse to activated the camera and watch me as I walk toward the right front tire. He saw mw as I approached, however, when I got right next to the tire I disappeared from she screen. GM said the vehicle was operating as designed. Operating as designed? They designed a SURROUND camera to show objects until they get next to the vehicle. Imagine if it was a toddler. | Crash: Yes Fire: No | Unknown |
| May 2023 | STEERING | Steering wheel stopped working | Crash: No Fire: No | Unknown |
| May 2023 | UNKNOWN OR OTHER | I have a GMC Sierra 2021 Denali. The vehicle currently has less than 16,000 mile and is at the dealership service department for lifter replacement. This is an extensive repair considering how new the vehicle with low miles. From extensive online research and collaborating with others, this is a common concern with multiple GMC vehicle that's been on GMC radar starting in 2017. GMC haven't yet issued a recall for these products and the consumers are footing the bills. Please put pressure on GMC to rectify their wrong. | Crash: No Fire: No | Unknown |
| May 2023 | ELECTRICAL SYSTEM | While towing a new 2023 Airstream trailer on Interstate route 95 in New Hampshire my GMC Sierra truck driver display flashes a " check Trailer wiring" error message. When this message appears all brake function to trailer is lost makeing driving unsafe. The connection sometimes can intermittently and continuously reconnect momentarily and brakes reengage for seconds until they disengage again with repeated "check Trailer wiring" error message . Sometimes the brakes just disengage end never reconnect until error codes is cleared by GMC dealership. It's extremely unsafe to pull off exit and have trailer brakes reengage because they jam with high gain because vehicle brakes need to be applied very hard to over compensate for "NO" trailer brakes. GMC dealership has identified certain error codes with their computer but NO suggested fix! | Crash: No Fire: No | Unknown |
| Apr 2023 | ENGINE | The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle was shaking with the check engine warning light illuminated. The independent mechanic was made aware of the failure; however, the vehicle was not diagnosed or repaired. The contact stated that the independent mechanic had previously replaced the lifters, but the failure recurred. The manufacturer was not made aware of the failure. The failure mileage was approximately 20,095. | Crash: No Fire: No | 20,095 |
| Apr 2023 | STEERING | My 2021 gmc Sierra displays (service power steering with care) the truck only has 13184 miles and barely moves. | Crash: No Fire: No | Unknown |
| Apr 2023 | TIRES | The contact owns a 2021 GMC Sierra 1500. The contact stated that the tire pressure warning light illuminated and that the TPMS sensor was not indicating the pressure for each tire. The vehicle was taken to the dealer and the dealer stated that no failure was found; however, the TPMS was reset, but the failure reoccurred. The vehicle was taken back to the dealer and the TPMS was reprogramed, but the failure persisted. The manufacturer was not contacted. The failure mileage was 5,000. | Crash: No Fire: No | 5,000 |
| Apr 2023 | STEERING,SERVICE BRAKES,ENGINE | While driving home from work around 6 am, my car had multiple warning lights and warning messages come up all of a sudden. Immediately after that I lost my power brakes and steering and was not able to control my car at 40 mph. I was lucky the light I passed was green and there was no other traffic. I was able to bring my truck to a stop after more than a quarter mile by putting all my weight on the brake pedal. The truck was towed to the dealer and has been there ever since. | Crash: No Fire: No | Unknown |
| Apr 2023 | STEERING | I parked my car for about an hour after driving for months with absolutely no issues or warnings. When I started my car and went to pull off the steering wheel locked up and I couldn’t turn it. A message appeared on the screen saying: Service power steering drive with care, and an esc message. A light also appeared. I turned the car off and let it sit for an hour. When I started it again everything worked fine. My dealership won't do anything because the warning codes went away, and the vehicle is not included in any current recalls. When looking up this problem it appears there are multiple recalls for the exact same issue on other 2021 Yukon and Tahoe models but not the Sierra. Though I see many forums and threads complaining about the same problem on the Sierra's. Since it is the same vehicle and systems as the Yukon, shouldn't the same recall apply? | Crash: No Fire: No | Unknown |
| Apr 2023 | ENGINE | DRIVING DOWN THE HIGHWAY THE ENGINE STARTED SKIPPING AND STARTED BLOWING OUT BLACK SMOKE, AND QUIT RUNNING IN THE MIDDLE OF THE HIGHWAY. FOUND OUT THE HAD A FACTORY LIFTER DEFECT ON MY MODEL AND A SERVICE UPDATE WAS SUPPOSED TO BE DONE ON THE TRUCK CHANGING OUT THE LIFTERS HOWEVER EVEN THOUGH I HAVE GONE TO DEALERSHIP FOR ALL THE MAINTENANCE THE SERVICE HAD NEVER BEEN DONE OR TOLD TO ME. THIS COULD HAVE BEEN VERY DANGEROUS JUST ENGINE FAILURE THE SERVICE BY GMC N212353840 | Crash: No Fire: No | Unknown |
| Apr 2023 | ENGINE | I was operating my vehicle in northern Minnesota with a temperature well below freezing. Vehicle warning light came on that said "turn off vehicle" which I did. When I went to start it again it would not turn over. It appeared that a large amount of oil had expelled from the vehicle. It was very dangerous as I was in a very remote area with very poor cell service and extremely cold temperatures. I couldn't even run the vehicle to stay warm. The vehicle was towed to the nearest GMC dealership where they examined the vehicle and stated that the seal of the oil filter had blown off. They further stated that the oil filter which was installed by Valvoline was the wrong size. Valvoline tested the Champion oil filter and came back with findings that the filter was the correct size and noted no damage to the filter. Either there is an unknown problem with the GM engine or the Champion oil filter. Each corporation continues to point fingers at each others product. | Crash: No Fire: No | Unknown |
| Mar 2023 | SERVICE BRAKES | I bought a loaner 2021 GM Sierra 1500 in Aug. 2021 from Starling Buick GMC, Venice, FL with 1600 miles on it. I used the Sierra to move items from my houses in my trailer from both FL to PA and PA to FL. On each trip The trailer brake controller would go out while driving. The first time it occurred was on a trip from FL to PA, during this trip it happened at least four times. Upon arrival in PA I took it to Kelly Buick GMC in Allentown, PA. They looked over the vehicle, saw there were codes in history indicating an issue with the trailer brake system but could not replicate it or pinpoint what part of the system was faulty. The dealer told me that GM will not fix it if it is in history only if it is currently giving a code. On the return trip back to FL from PA, same thing several times it occurred, took it back to the selling dealer Starling, and they gave me the same speech as Kelly , can't fix it without a current code. Next trip from FL to PA, same thing took it to Kelly again, same response. Back to FL from PA, same thing, Starling gave me the same response, they can't and won't do anything. I told Starling service rep I guess I need to die before you do anything, she was completely indifferent to my comment and backed GM without any regard for my safety. It is sporadic and inconsistent and obviously only occurs when there is a trailer attached. They said it was my trailer so I took it to a trailer mechanic, we tested it on its own and on another vehicle with no problem. The brake controller failed while hauling a trailer potentially allowing a serious if not deadly accident with improper braking capabilities. Even though two dealers in two different states acknowledge there is an issue they refuse to correct it because they can not replicate it. The brake controller lights would go out as you're driving indicating the brake controller is not connected to the trailer and providing a supplemental braking system. 2022 and 2023 have this issue. | Crash: No Fire: No | Unknown |
| Feb 2023 | ELECTRICAL SYSTEM,ENGINE,FUEL/PROPULSION SYSTEM | Less than 5 minutes after my husband and 2 children parked the car and came inside, a neighbor walking rang our doorbell to let us know there was something on fire in our driveway. We ran to the back to find his truck engulfed in flames coming from the engine. We quickly called 911 and exited the house/property. The truck continued to burn with 20-25 foot flames and very black smoke for about 40 minutes until the fire department was able to control the fire. The fire was hot enough that the entire engine was significantly burnt, the seats and steering wheel were gone, the glass shattered and melted, and the tires exploded and melted. Thankfully, everyone was out of harms way and safe through this incident. However, it has been extremely traumatic on my family and neighbors and has taken a lot of time and energy to try to deal with this. The car sat in our driveway for over 2 weeks with a very potent smell causing headaches until GM and our insurance finally investigated. There is damage to our siding, driveway, landscaping, basketball hoop, trampoline, and neighbors fence. The car was only 2 years old and scares me how quickly it went up in flames and how much worse this could have been either 3 minutes earlier or if it was parked in our garage. | Crash: No Fire: Yes | Unknown |
| Jan 2023 | AIR BAGS,SEAT BELTS | I get a "Service Safety Restraint System" warning sporadically when driving. No known cause and the vehicle has never been in an accident. This started happening after my last service at Capital Buick GMC in Smyrna, GA on January 6th, 2023. | Crash: No Fire: No | Unknown |
| Jan 2023 | ENGINE | 2021 GMC Sierra 1500 AT4 6.2L engine, Little over 39000 miles, Purchesed May 2021. This is the second time the vehicle has had this issue. The first time was aprox 15000 miles. I reported the issue to NHTSA-ODI on 6 Dec 2021 tracking # 11442943. I was driving down the interstate I heard a rattling coming from the engine (same as I had heard with the first issue). The check engine came on I ask On Star to do a digonsotic report (see attached report). The report indicated a Fuel Management System issue detected advised to reduce vehicle speed and pay load as possible. I was told by GM certified mechanics that this issue could cause the engine to lock up and come to a complete stop on the roadway. I fill that these vehicle are unsafe to operate under these conditions and may cause serious accidents. GM has known about these issues with these vehicles for several years and has failed to correct the problem. | Crash: No Fire: No | Unknown |
| Jan 2023 | ELECTRICAL SYSTEM | The contact owns a 2021 GMC Sierra 1500. The contact stated while driving at various speeds with the ONSTAR/GPS, turn-by-turn driving directions activated, there was an unknown notification flashing on the instrument panel and radio. The speedometer was obstructed and failed to work as needed. The screen sporadically went blank. While depressing the dismiss button on the steering wheel, the button failed to correct the failure. There were no warning lights illuminated. The vehicle was taken to the local dealer and the system was rebooted; however, the failure recurred. The vehicle was taken back to the local dealer and the contact was informed to turn off the vehicle, open the door, and then restart the vehicle to reboot the vehicle. The vehicle was taken to another local dealer, Bill Cramer Chevrolet Buick GMC (2251 W 23rd St, Panama City, FL 32405) but the vehicle was not diagnosed or repaired. The manufacturer was contacted but no additional assistance was provided. The failure mileage was approximately 10,450. | Crash: No Fire: No | 10,450 |
| Jan 2023 | ELECTRICAL SYSTEM | My truck’s battery is dead after sitting for a few days. There is a manufacturing deficit causing parasitic draw. This is a safety issue because it leaves us stranded after parking the vehicle for a few days. The General Motors dealership refuses to do it anything about it. They claim it’s normal. | Crash: No Fire: No | Unknown |
| Jan 2023 | EXTERIOR LIGHTING | During winter/snow driving snow accumulates on the headlights and causes a partial to total loss of visibility. This has happened multiple times during winter months. Cleaning the headlights requires exiting the vehicle in a potentially dangerous situation. This may occur after every few miles or less depending on the conditions. | Crash: No Fire: No | Unknown |
| Dec 2022 | ENGINE,FUEL/PROPULSION SYSTEM | 15000 MILES LIFTER FAILURE IN TRAFFIC HIGHWAY AT SPEED 70 MPH LOST POWER ENGINE FAILED MULTILANE HIGHWAY RUSH HOUR TRAFFIC NO WARNING FAILURE | Crash: No Fire: No | Unknown |
| Dec 2022 | UNKNOWN OR OTHER | I have a 2021 GC Sierra 1500, The guidance lines in the display when in reverse go from non-existent to barely visible and are not usable especially in sunlight. The service man at Miller Chevrolet in Marianna Fla says GMC is aware of the problem, that it was caused by the last update download and will be fixed by another download to correct the problem. He also says the same issue is nationwide and all trucks have the issue which I find hard to believe. 1.If that were true it would be a simple matter of a few lines of code to correct the problem. 2. I have been chasing this problem since October and have now made four trips to the dealership. 3. I cannot believe all trucks have this issue and also I suspect the same backup system is in all GMC vehicles regardless of type. 4. I cannot believe GMC would allow such a problem to exist since the last update download which was months ago. 5. I contacted GMC Customer Care in October after the dealership told me they had no idea what was causing the issue. I have had a case number [XXX] since that time. I was told on the first call that if necessary a Tech would be sent to fix the problem. Today I called asking for a tech to be sent only to be told I had to take it to another dealership and try them before a Tech could be sent! I have two questions, can you help with this and does this qualify as a "lemon law" case? Any assistance would be greatly appreciated. INFORMATION Redacted PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6). | Crash: No Fire: No | Unknown |
| Dec 2022 | SERVICE BRAKES | All 4 brake rotors are warped according to my local GMC dealership. They also told me all of the inside brake pads are worn twice as much as the outer pads, which in my opinion indicates a manufacturing and/or computer controller issue. Safety is an issue when the inside brake pad wears down to metal while the outers are still over 75% of new thickness. GMC dealer told me they're seeing this on countless Sierra trucks made in the past few years but there is no recall and GMC will not cover it under warranty. First symptom was slight pulsing while braking downhill. 2-3 weeks later my brake pad wear indicator read 82% front, 88% rear. The following day it gave me an error message saying "service brake monitor" so I took it to my GMC dealer which is when they told me my brake pads and rotors all need to be replaced but the truck only had 22800 miles on it at that time. They said it could still be driven and pass inspection. Since then I have contacted GMC about them covering it and I have not made any progress. GMC has had numerous brake issues resulting in recalls in the past 3-6 years but unfortunately this particular issue has not yet reached recall status. I hope this gets resolved before I am forced to pay for brake replacements out of pocket, which nobody should have to do on a vehicle with so little miles on it. The work order invoice I uploaded indicates ""pads at wear limit, both front and rear" but it does not specify what the technician and service advisor told me regarding only the inside pads are worn. However I do have a recording of the service advisor telling me that if needed. You'll also notice that I uploaded a copy of the state inspection done by them that same day which indicates my brake system passed the requirements. Please help. | Crash: No Fire: No | Unknown |
| Nov 2022 | FUEL/PROPULSION SYSTEM,FUEL SYSTEM, DIESEL | Within 100 miles after purchasing this truck from GMC (used with 74K miles)I got messages both on my phone and later through inspection at GMC service center that the DEF system had a problem. The check engine light came on then off as well.I was getting messages saying I only had so many miles before the DEF system needed more fluid even though the tank was full or near full. The dealer here in Tucson indicated there was a bulletin on this problem and ordered parts for the repair. I was informed it was not a recall and I would have to pay over $800.00 for this repair. To date the dealer has had my truck for 2 weeks. Additionally, another message said insufficient coolant flow so they are installing a new coolant pump to be paid for by an after market warranty which I purchased at the time I bought the truck. This repair is over $1000.00 | Crash: No Fire: No | Unknown |
| Nov 2022 | SERVICE BRAKES | The contact owns a 2021 GMC Sierra 1500. The contact stated that the grandson was driving in stop-and-go traffic, the braking system suddenly malfunctioned causing the vehicle to crash into the rear of a second vehicle. The grandson was driving approximately 10 MPH when suddenly while pressing the brake pedal to stop the message "brake failure" displayed before the vehicle crashed into the rear of the second vehicle. During the crash, no injuries were reported and a police report was taken at the scene. The vehicle was taken to the local dealer who replaced the master cylinder and brake booster and the failure was remedied. The failure mileage was 21,539 | Crash: Yes Fire: No | 21,539 |
| Oct 2022 | ELECTRICAL SYSTEM,ENGINE | The contact owns a 2021 GMC Sierra 1500. The contact stated that while operating the vehicle, the dashboard gauges, instrument cluster, and infotainment center malfunctioned and became inoperable. Additionally, while starting the vehicle, there was a loud cranking sound coming from the engine compartment and the vehicle would not immediately start. The vehicle was taken to the local dealer, but the cause of the failure was not yet determined. The manufacturer was notified of the failure, but no assistance was offered. The failure mileage was 100. | Crash: No Fire: No | 100 |