2020 GMC Sierra 3500 problems
NHTSA has received 72 complaints about the 2020 GMC Sierra 3500, and 26% of them involve drivetrain & axles. After that come electrical system (12%) and brakes (10%).
At a glance
- Complaints
- 72 filed with NHTSA
- Most reported
- Drivetrain & axles 26% of complaints
- Crashes and fires
- 6 and 4
- Injuries and deaths
- 4 and 0
- Typical mileage
- 29,000 miles 12 complaints with mileage
Source: NHTSA owner complaints
Where the complaints are
Share of this model year's complaints by the part of the car involved. One complaint can name more than one part, so the shares can add up to more than 100%.
When problems show up
View the numbers
| Mileage | Complaints |
|---|---|
| 0k to 20k miles | 4 |
| 20k to 40k miles | 3 |
| 40k to 60k miles | 3 |
| 60k to 80k miles | 0 |
| 80k to 100k miles | 0 |
| 100k to 120k miles | 1 |
| 120k to 140k miles | 1 |
| 140k to 160k miles | 0 |
| 160k to 180k miles | 0 |
| 180k to 200k miles | 0 |
| 200k+ miles | 0 |
What the data shows
Among the 12 complaints that report mileage, the typical (median) problem appeared at about 29,000 miles.
Safety-related details: 6 complaints mention a crash; 4 complaints mention a fire; 4 injuries reported.
Looking only at complaints filed within five years of the model year (so older and newer years are comparable), the 2020 ranks 2nd most-complained-about out of 15 model years of the GMC Sierra 3500 with enough data (69 complaints in that window). It is also covered by 8 safety recall campaigns.
What owners wrote
A few complaints as filed, shortened and with personal details removed. The first ones are among the most serious reports for this model year; the rest are typical.
While towing a fifth wheel camper, the exhaust was so hot it melted the camper directly behind it. Was caught in side mirror before anything caught on fire.
The contact owned a 2022 GMC Sierra. The contact stated that while her husband was driving at an undisclosed speed, the vehicle collided head-on with another vehicle that ran a red light. The air bags did not deploy. No warning lights were illuminated. A police report was filed. No injuries were reported, but the contact and her husband sought medical treatment for various bruises caused by the seat belt at a later date.
driving approximately 50 mph when vehicle suddenly made loud bang and locked up rear brakes for 25' coming to a stop in road side ditch, numerous vehicles had to make evasive actions to avoid me and other vehicles. flat spotted tire abut no visible physical damage. sat on side of road for transmission temp to cool down then drove to shop without repeat. called dealer was told the earliest appt was a month away. have not been able to repeat incident so far.
The contact owns a 2020 GMC Sierra 3500. The contact stated while driving approximately 60 MPH, the vehicle jerked, lost motive power, and almost stopped unintendedly. There was no warning light illuminated. The contact was able to pull into a parking lot, where the vehicle shut off. The contact stated that while attempting to restart the vehicle, the diagnostic trouble code: P129F was displayed, and the vehicle failed to restart. The vehicle was towed to the residence.
The contact owns a 2020 GMC Sierra 3500. The contact stated that while driving 45 MPH with passengers seated in the rear seats, the passengers became aware that water was entering the vehicle between the window and frame. There were no warning lights illuminated. The vehicle was taken to the local dealer, who informed the contact of Technical Service Bulletin: 18-NA-383. The vehicle was not diagnosed or repaired.