GMC Sierra Complaints (2020)

626 consumer complaints on file.

#11664079May 31, 2025
ENGINE
Misfire alerts causing major motor repairs
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11663591May 29, 2025
ENGINE
My 5.3 engine spun a bearing on the crank. Same exact problem the 6.2 got recalled for. Now if I put a used engine in it’ll cost me around $6,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11663601May 29, 2025
POWER TRAIN, ENGINE, UNKNOWN OR OTHER
TRANSMISSION SHURTTING, JERKS, AND VIBRATION, BAD TORQUE CONVERTER BUBBLE AND PELLING PAINT. IT FEEL LIKES ENGINE IS LOSSING POWER
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11663186May 27, 2025
ENGINE, UNKNOWN OR OTHER
6.2 liter engine fail- replaced at new cost, 20,000 miles later another 6.2 engine failed. unable to get new engine due to GMC finally recalling the engine. My VIN is not included in the recall. I now have no vehicle to drive but still have a loan to pay.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11663023May 25, 2025
ENGINE
Driving at freeway at 65mph, suddenly is air noise like air conditioning blows air at high fan speed, than the dash info shows (Engine Power is Reduce) try to accelerate to pull out of lanes, and it did not, keep losing speed, as slowly move lanes to the right of freeway, and then exit.. This is the second time of this incident, first time under warranty, dealer fix transmission first time, then two months later, the tansmission was replace wit a newone, now is passed warranty, had the car taken to dealer, they gave me and estimate of more then $10,000 to fix the vehicle, this happen on May 21, 2025...
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11662870May 23, 2025
POWER TRAIN
Transmission valve control malfunctioned, causing rear wheels to temporarily lock, skidding the tires. This almost caused me to loose control, endangering myself and others around me. This is the second time this problem has happened. A recall related to this was addressed on this truck, though it has clearly done nothing to prevent it from happening.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11662873May 23, 2025
POWER TRAIN
Transmission valve control system malfunctioned, causing rear wheels to lock up at high speeds, in turn causing tires to skid out. This issue almost caused me to loose control of the vehicle, potentially endangering the safety of myself and others near me at the time. This is the second time this has happened while I have been driving this vehicle. There was a recall related to this issue, which was addressed, but very clearly did absolutely nothing to prevent this incident from occurring.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11662486May 22, 2025
ENGINE, POWER TRAIN, UNKNOWN OR OTHER
Vehicle drop in gear / down shift while driving on the highway. went from 75MPH down to 55MPH due to high RPM revs.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11662487May 22, 2025
ELECTRICAL SYSTEM, ENGINE, POWER TRAIN
Vehicle Stuck in gear. Dealership was delivering the car back to myself when about a mile out from my house when the vehicles made a sudden downshift and was stuck back in gear. Driver called and notified me that it was on its way back to the shop for further work
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11662488May 22, 2025
ELECTRICAL SYSTEM
While driving my vehicle it began down shifting harder than normal (at various speeds and road (highway, city and dirt road)); along with a noticeable burning smell after every trip. GM Maintenance personnel discovered that the wire was chafed and arching / catching on fire underneath passenger side resulting in the burning smell and the wiring issue aligned to the transmission. Personnel took a video and provided to me as evidence of the fire / smell; however, that was on their official GM app so i was unable to download
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11662489May 22, 2025
UNKNOWN OR OTHER
Engine light came on while driving / aligned to transmission temp sensor error and brake sensor GM Maintenance was able to diagnosis that the Temperature Loop Coolant Pump had failed and needed to be replaced.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11662491May 22, 2025
ENGINE, UNKNOWN OR OTHER
No warning; picking up child from daycare. went to depart daycare when my dash lit up like a Christmas tree with various errors, alerts, warnings; along with, not being able to start. had to be picked up by spouse and get the truck towed to the dealership for maintenance. Maintenance tech discovered that the grounding straps for the truck needed to be replaced / resulting in a complete electrical failure of the vehicle.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11662494May 22, 2025
ELECTRICAL SYSTEM
After repair got a few miles down the road and noticed the volt meter jumping back and forth between the white lines. Line would slowly go up to max line and then slowly drop back down to lower limit and continue to go back and forth. This was very concerning to myself and i was waiting for something to fail while driving. Got about 10 miles away and was to concerned / returned the vehicle Informed by GM Maintenance tech that this is what / how the vehicle is designed and that it is the operating within its parameters. I expressed that only time i noticed something like this was prior to an engine light / electrical failure; however, maintenance team expressed GMs stance that it is operating within tolerance.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11662496May 22, 2025
ENGINE, ELECTRICAL SYSTEM, POWER TRAIN
Engine light came on and real bad urine smell / burning coming from the vehicle / rough performance. This issue occurred at various speeds / trips / drive types with the only variation being speed from 25MPH to 75MPH. Vehicle went in to discover that the reductant control module software (RCM) out of date, and two NOx sensor failures
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11662497May 22, 2025
ENGINE, POWER TRAIN, UNKNOWN OR OTHER
Vehicle was going in for warranty recall; however, i requested they look at the DEF system as my DEF gauge would bounce between full and empty; along with, alert me of going into LIMP mode. GM Maintenance updated the recall and noticed that the DEF tank sensor failed and required to be replaced.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11662500May 22, 2025
ELECTRICAL SYSTEM, ENGINE, POWER TRAIN
Engine light would come on for a few days and than turn itself off. this occurred for about 8/9 months; however, instructed by the GM Maintenance department that if the vehicle came in and the light turned off before they got to it i would be charged for the diagnosis and no work would be performed. Engine light came on and i was able to park the vehicle / they picked it up and read it prior to putting in their lot until a tech became available. GM Maintenance was able to diagnosis that there was an issue with the EGR sensor and NOx catalytic converter without filter failed / both items replaced
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11662504May 22, 2025
ENGINE, ELECTRICAL SYSTEM, POWER TRAIN
Engine Light came on, performance rough at various speeds / conditions, and smelled like burning and strong urea smell. GM Maintenance identified a failed DEF injector / replaced
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11662251May 21, 2025
UNKNOWN OR OTHER
Rear window is leaking top coners from seal or plastic creating black mold inside of truck
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11662257May 21, 2025
SERVICE BRAKES, ENGINE, UNKNOWN OR OTHER
Engine started skipping, then service parking brake light came on, then service engine light came on and speed dropped to 44 mph.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11662292May 21, 2025
ENGINE
The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle jerked while accelerating and while coming to a stop. The check engine warning light was illuminated. The vehicle was taken to the dealer, but no cause of failure was found. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 65,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0

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