Problems · NHTSA complaints

2020 GMC Sierra problems

Owners filed 495 complaints about the 2020 GMC Sierra with NHTSA between Dec 2019 and Oct 2026. The most-cited component is engine (251).

Complaints
495
Filed with NHTSA
Crashes
12
Reported by owners
Fires
5
Reported by owners
Injuries
13
People reported injured
Deaths
0
Reported to NHTSA
01 —By component

Complaints by component

One complaint can cite several components
  1. Engine251
  2. Power train99
  3. Electrical system82
  4. Service brakes51
  5. Steering38
  6. Fuel/propulsion system27
  7. Engine and engine cooling22
  8. Suspension18
  9. Forward collision avoidance16
  10. Structure13
  11. Vehicle speed control12
  12. Visibility/wiper12
  13. Electronic stability control (esc)6
  14. Air bags6

Complaints are unverified owner reports to NHTSA and are not normalized for sales volume. One complaint can cite several components.

Data from NHTSA Complaints API · synced Nov 4, 2026NHTSA vehicle page
02 —Trend

When complaints were filed

Does it get worse with age? Complaints per calendar year filed
View as table
Model yearComplaints filed per calendar year
20191
202042
202137
202223
202324
202440
2025189
2026139

Mileage at failure isn’t a structured field in NHTSA complaint data, so we don’t chart it. Some owners mention it in their reports below.

03 —Owner reports

Top problems in owners’ words

Verbatim from NHTSA complaints, newest first

Engine

251 reports3 crashes1 fire
“6.2 liter engine failed at 59,300 miles. Being replaced right now with remanufactured engine. 2020 GMC Sierra is not part of recall but others have had problems as well”
Owner complaint to NHTSAFiled Oct 28, 2026EngineODI 11774319

Power train

99 reports1 crash3 related recalls
“I own a 2020 GMC sierra AT4. It has developed a shudder when cruising on the highway or driving in town around 1500rpm. I believe it is coming from the transmission. A local shop mentioned the torque converter. The shudder feels like a delay in power and makes it difficult to hold speed or accelerate when needed.”
Owner complaint to NHTSAFiled Oct 23, 2026Power train, EngineODI 11773333

Electrical system

82 reports2 fires1 related recall
“The contact owns a 2020 GMC Sierra 1500. The contact stated that the vehicle failed to start intermittently and needed to be jumpstarted. The vehicle was taken to the dealer, and it was determined that there was corrosion on the ground wire which caused the failure. The vehicle was not repaired because the vehicle was not included in Customer Satisfaction Program: N252515590 with NHTSA ID Number: 11027795 (Electrical System) for the ground wire replacement. The manufacturer was informed of the failure and confirmed that the vehicle was not covered. The manufacturer referred the contact to the NHTSA Hotline to report the failure. The failure mileage was approximately 51,000.”
Owner complaint to NHTSAFiled Oct 7, 2026Electrical systemODI 11769576

Service brakes

51 reports3 crashes1 fire
“Lifter failed due to AFM system. Cyl 8 misfire due to oil fouling. The onboard computer got confused and would not release the parking brake until repeated attemtps to release it. 5.3L V8 2020 model year 115250 miles. Isn't this the same problem as the 2021 and newer engines? 8spd transmission. AFM failure. 9k repair.”
Owner complaint to NHTSAFiled Sep 7, 2026Service brakes, EngineODI 11762548

Steering

38 reports1 crash
“This morning it seems as if my 6.2L GM motor threw a rod. All the initial sounds and check engine information point toward that. I will be taking it to a dealer to confirm the issue. Data center driving ability and sounds indicate steering was affected as well or is somehow connected.”
Owner complaint to NHTSAFiled Oct 23, 2026Steering, EngineODI 11773206

Fuel/propulsion system

27 reports1 crash
“[XXX] General Motors Company P.O. Box 33170 Detroit, MI 48232-5170 c/o Franklin, Customer Support Re: Formal Demand for Buyback – 2020 GMC Sierra AT4 Black Widow VIN: [XXX] | 6.2L Engine Recall ~ 25V-274. Plus ~ GM 10-Speed Transmission, Multiple Recalls Dear GMC Legal, I am providing written notice as required by 15 U.S.C. §2310 and New York State Lemon Law. This vehicle substantially impairs the safety, use, and value of my truck, and I am requesting a full buyback. The Facts: On [XXX], the vehicle was taken out of service and remained at the shop for 11 weeks. It was returned with yellow marking paint splattered on the exterior, floor mats, and brake pedal. On [XXX] — with fewer than 400 miles on the replacement engine — the engine and/or transmission suddenly shut off at 55 mph on [XXX]. It restarted with a violent boom, then cycled between shutting off and restarting with loud clacking and shaking for the remainder of the drive. I was forced to drive at 25 mph with hazard lights to reach home. The Legal Basis: This is a safety defect on a vehicle subject to Recall 25V-274. GM was on notice of this known, concealed defect. The vehicle has been out of…”
Owner complaint to NHTSAFiled Oct 17, 2026Power train, Engine, Fuel/propulsion systemODI 11771820
Data from NHTSA Complaints API (owner reports, unverified) · synced Nov 4, 2026

Complaints are unverified owner reports to NHTSA and are not normalized for sales volume. One complaint can cite several components.