Home · 2020 GMC Sierra 2500 Hd · Complaints

What 73 owners told NHTSA about the 2020 GMC Sierra 2500 Hd

These are the actual owner complaints behind this car’s reliability verdict, filed with the federal government, unedited. They’re unverified reports, not confirmed defects: read them as leads for your pre-purchase inspection, not a diagnosis.

All (73)Crash / fire / injury (4)Transmission & drivetrain (22)Brakes (12)Electrical system (12)Engine (10)Steering (6)Body & structure (5)Driver assistance (4)Speed control (3)Engine & cooling (2)Lights (2)

4 of 73 complaints match · Driver assistance · clear filters

Dec 20, 2025Electrical systemBrakesDriver assistance

The main tailgate will not go down or function properly and it says online there is a national recall for this, but does not come up when I search my vehicle. When I turn on my left turn signal the brights flash for no reason and this is a known major issue with the vehicles as well. The trucks computer is telling me low on coolant even though it is not that has already been fixed through a 3rd pARTY WARRANTY Parking brake was stuck on when I bought the vehicle and had been for a long time you could tell and I had to pay over $1100 to fix it at GM. The Ford collision system does not work properly and the cameras will come on at certain times when they're not supposed to be and not come on when they are supposed to be

NHTSA ODI 11706292

Jun 17, 2024Driver assistance

The contact owns a 2020 GMC Sierra 2500. The contact stated while driving 60 MPH, the vehicle independently slowed and dramatically decelerated. The vehicle returned to normal functionality, but the failure became a regular occurrence. The contact stated that when the failure occurred, the gear shifter position indicator light flashed, and once the vehicle returned to normal functionality, the light remained solid. No warning lights were illuminated. The vehicle was taken to the dealer, who diagnosed a failure with the Forward Collision Avoidance warning sensor. The vehicle was repaired, but the failure reoccurred. The manufacturer was not notified of the failure. The failure mileage was 102,000.

NHTSA ODI 11594842

Mar 29, 2024BrakesDriver assistance

My vehicle inadvertently locks the rear tires at highway speeds and then releases and drives. In some instances it may brake several times causing the tires to burn rubber for a short distance causing rear traffic to either swerve to avoid rear ending me and in a couple instances causes the rear following traffic to abruptly change lanes to avoid rear ending me

NHTSA ODI 11580026

Dec 17, 2021Driver assistance

Was driving truck down driveway at about 5km per hour and the parking brake automatically engage bringing the vehicle to a sudden and unexpected hard stop. Brought to dealership, then said they cannot duplicate the problem and therefore there is no action to be taken.

NHTSA ODI 11444113

Working with the data? Download all 73 complaints as CSV · fetched from NHTSA July 19, 2026

How to use these: a complaint is one owner’s report, filed voluntarily and published unverified. Patterns matter more than any single story. If several owners describe the same failure at similar mileage, put that system at the top of your pre-purchase inspection list. Back to the full 2020 GMC Sierra 2500 Hd verdict →