2025 GMC Sierra 3500 problems
NHTSA has received 27 complaints about the 2025 GMC Sierra 3500, and 19% of them involve brakes. After that come electrical system (15%) and engine (15%).
At a glance
- Complaints
- 27 filed with NHTSA
- Most reported
- Brakes 19% of complaints
- Crashes and fires
- 0 and 0
- Injuries and deaths
- 0 and 0
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%.
What the data shows
None of these complaints report a crash, fire, injury or death. Its complaints are less severe on average than those of 100% of model years in our database.
Looking only at complaints filed within five years of the model year (so older and newer years are comparable), the 2025 ranks 7th most-complained-about out of 15 model years of the GMC Sierra 3500 with enough data (27 complaints in that window). It is also covered by 1 safety recall campaign.
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.
Intermittent loss of trailer brake function. While traveling and towing a RV trailer with electric brakes, receive a dashboard alert that trailer brakes have been disconnected. This has occurred since vehicle was new. Trailer brake system has been inspected and trailer is not the issue. Took truck to GMC dealer. They are well aware of common issue with GMC owners. GMC issued a safety bulletin 6+ months ago to dealers to replace the integrated trailer brake controller (RPO code JL1).
While towing my fifth wheel trailer, the truck intermittently disconnects the trailer brakes while in motion. This results in a sudden loss of roughly 75% of my braking capability, creating an extremely dangerous situation. I have a professional driving background, which has helped me avoid an accident so far, but this issue could easily result in a collision, especially under emergency braking or downhill conditions Service Attempt: On June 17, 2025, I brought the vehicle to Madras Chevrolet in Oregon.
The contact owns a 2025 GMC Sierra 3500. The contact stated that the transmission was shifting hard and was jerking while shifting gear. Additionally, the vehicle failed to accelerate above 50 MPH. The messages “Reduced Acceleration” and “DEF Low” were displayed. While refueling the vehicle, the fuel gauge failed to correctly display the level of fuel inside the fuel tank until the vehicle had been driven for approximately 20 minutes.