2020 GMC Sierra 3500 Brakes Problems
- Complaints
- 7about this part
- Share
- 14%of 51 total for the year
- Median mileage
- —not reported
- Trend
- Not enough dataFewer than 15 complaints, too few for a reliable trend.
NHTSA recorded 7 complaints about the brakes of the 2020 GMC Sierra 3500, 14% of the 51 complaints for this model year. 1 of these say a crash was involved, according to the filers.
Fewer than 15 complaints name this part, so treat the figures as a rough indication only.
Example complaints
Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.
“The computer malfunctions. It is available for inspection. The computer lights up and causes failure in the trailer brakes. Glenn Polk the dealership in Sanger Texas has been working on a fix but has yet to come up with one. I have spoken with General Motors Representatives several time trying to resolve the problem without result. I also emailed the CEO last Friday and have heard nothing. There were no warning lights until seconds before failure.”
NHTSA complaint #11418543, filed 2021-05“The computer lights up the dash reducing power and turning off power to trailer brakes. This has almost caused an accident on several occasions . It happens a couple of times per trips. This vehicle has been in the shop a couple of times per month since it was put into service. Glenn Polk Chevrolet has worked on it each time and the problem is still there. This truck has also had several injector issues. There is an open case with this vehicle with General Motors with no resolution. I have filled out forms on each of my 2020 GMC's 3500's.”
NHTSA complaint #11418621, filed 2021-05“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. …”
NHTSA complaint #11598428, filed 2024-07“The computer lights up dash reducing power and taking the trailer brakes away. This almost caused a wreck when the truck shut off and the brakes failed. This truck has been in the shop at least once per month trying to fix the issues, from computer and brake failure to injector failure. Glenn Polk Chevrolet in Sanger has been working on this since the truck was new. Also we have case open with General Motors without resolution. The dash lights up at the same time as the brakes fail.”
NHTSA complaint #11418617, filed 2021-05“The computer lite up the dash and reduced power, plus took the trailer brakes off line. This happened while loaded. To reset the system you have to pull over and turn the vehicle off. This happens 2-3 times per day. This was a problem at 600 miles. The transmission shifted from 10 gear to 5th gear while driving 75 miles per hour. The truck had 75,000 miles on it . Had to send another truck out to pick up the load in Santa Rosa New Mexico. The dealer Glenn Polk in Sanger has been working on for the last 4 months There is never a warning until the lights come on with a system failure.”
NHTSA complaint #11418595, filed 2021-05Related service bulletins
- 11017173Mar 21, 2025This informational bulletin instructs the tech when fuel/fluid is needed to be tested and where it can be sent for analysis.
- 11014230Jan 31, 2025This bulletin advises the dealers to maintain the vehicle stock on hand by doing a full inspection on the vehicles before being sold (prepping) to the customer.
- 11013242Jan 17, 2025This informational bulletin advises the technician to check for faults that may be caused by the trailer otherwise found by a possible faulty trailer connector.
- 11012938Jan 9, 2025This Preliminary Information communication provides information to the technician about customers that may request the factory Integrated Trailer Brake Controller Regular…
- 11011709Nov 5, 2024This bulletin advises the dealers to maintain the vehicle stock on hand by doing a full inspection on the vehicles before being sold (prepping) to the customer.
- 11011018Oct 22, 2024This informational bulletin provides an optional repair using a different set of brakes that may correct the customers concern of Early Brake Wear in Harsh Environments.
- 11009463Sep 25, 2024This service bulletin provides repair information to correct customer concerns of Rear Wheel Lock Up, ABS Event, Loud Bang and a Flashing “D” on Driver Information Center (DIC)…
Brakes: other model years
| Year | Complaints | Share of year |
|---|---|---|
| 2026 | 1 | 20% |
| 2025 | 5 | 29% |
| 2024 | 11 | 22% |
| 2023 | 2 | 7% |
| 2022 | 4 | 13% |
| 2021 | 5 | 25% |
| 2020 | 7 | 14% |
| 2019 | 4 | 31% |
| 2018 | 6 | 43% |
| 2017 | 5 | 38% |
| 2016 | 6 | 32% |
| 2015 | 4 | 13% |
| 2014 | 1 | 14% |
| 2013 | 1 | 7% |
| 2012 | 1 | 11% |
| 2008 | 1 | 4% |
| 2007 | 3 | 19% |
| 2006 | 2 | 18% |
| 2005 | 10 | 42% |
| 2004 | 14 | 58% |
| 2003 | 3 | 43% |
| 2002 | 9 | 45% |
| 2001 | 16 | 44% |
| 2000 | 12 | 46% |
| 1999 | 9 | 47% |
| 1998 | 4 | 33% |
| 1997 | 4 | 40% |
Other parts of the 2020 GMC Sierra 3500
19 complaintsElectrical system
9 complaintsEngine
6 complaintsFuel system
6 complaintsOther or unknown
6 complaintsBody and structure
5 complaintsTires
4 complaintsVisibility (wipers, defrost, mirrors)
2 complaintsAir bags
1 complaintsEngine cooling
1 complaintsExterior lighting
1 complaintsForward collision avoidance
1 complaints
← All problems reported for the 2020 GMC Sierra 3500
About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 31, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.
To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology