Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2015 GMC Yukon XL owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2015 GMC Yukon XL. The contact stated that while driving 70 MPH and exiting the highway, the brake pedal was depressed but the brake pedal was stiff and stuck, requiring that the transmission be shifted to neutral(N), and to stand on the brake pedal with both feet. The contact continuously pumped the brake pedal, but the vehicle slowly responded and almost crashed into other vehicles. There was no warning light illuminated. The contact's wife and daughter were also inside the vehicle during the failure and were frightened and concerned for their safety during the failure. The dealer was contacted and was provided a description of the failure over the phone. The dealer informed the contact that the vacuum pump and an unknown part had possibly failed. …
I was dropping my daughter off at school in the car line. I was at low speed trying to brake and with the brake all the way down couldn't stop immediately. I was able to stop but then went to go again and when tried to stop again, couldn't and hit the car in front of me. It was making a sound while trying to brake but wouldn't engage my brakes. Luckily it didn't leave any damage and the other driver said it was OK and accepted my apology as my brakes were not working correctly.
This is a complaint for my vehicle Gmc2015 Yukon. My Truck brake system(vacuum pump is defective). my large truck is a safety hazard on highway and street . when i attempted to park while depressing my brake pedal it instantly before very hard to press to stop my truck. i have to apply lot of force to my foot inorder to stop vehicle. my mechanic inspected vehicle and it show a bad (defective vacuum pump) . base on former complaints about this same problem (2019 NHSTA campaign number 19v645000 ) it show and state the exact problem with my vehicle. this problem started early last year. Also, when driving on highway and slows down,the brake vacuum pump and brake pedal locks up (very difficult to stop something). this happens intermitting times. very scary trying to stop from crashing into cars in front of me sometime.
This vehicle was purchased on 7/05/2019 with miles 52,000 and the TRAILER BREAKE SYSTEM has gone bad 2 times already and I haven't never used the trailer hook for anything is just so expensive to fixed it and goes bad again and all part we're purchased from the dealership even the dealer said is a manufacturer error and this will keep happening because is manufacturer error was not designed correctly as a consumer I feel that I shouldn't be paying for their mistake GMC should do recall and get this issue fixed as soon as possible and fixed it 2 times I have been at the dealership to get this issue fixed and I'll probably be back again to get fixed and like mentioned is not cheap to fixed please do something about this matter I'll gladly appreciate
I purchased a 2015 GMC Yukon in March 2024 I drive the vehicle 9 mons, 7500 miles the vehicle has been in service at my local dealership since Dec 13, 2024, for engine and transmission replacement, I have had the vehicle back 3 weeks not the warning light and service warning chime for the "Service Trailer Brake System is on, I have not ever use a trailer with the vehicle, I was told the vehicle needs a wire harness, I have read this a problem in these vehicles that has not been addressed GMC with a recall, I have put A LOT of money in the vehicle. This is an well documented failure in the trailer brake system that GM should repair at no cost to the consumer
The service brake assist warning message keeps appearing. Additionally, when the vehicle is completely stopped, but then you let off the brake to roll forward a little bit (such as at a stoplight), when you press the brake again it does not have stopping power. Must pump the brake several times as the vehicle rolls. This is particularly dangerous in downhill stops. It appears there is a safety recall on the power assist vacuum for brakes on 2015 GMC Yukon XL, but for some reason, my VIN is not included in the recall. I would like to know what it would take to include my VIN in the recall because it is the same year, make, and model.
Service Box appears indicating - "Trailer Brake System" with a loud BING, BING, BING Alert sound. It continues every few minutes... Please note: we aren't using a trailer... I have googled/youtube it and found that this is an issue with many owners. They indicate that the wire harness in between two of the body control modules is defective. It is known to have faulty wire connection. This is intermittent, goes for months and stops for months, and then starts up again. Starting the vehicle, while driving slow or fast, it doesn't matter.
My power vacuum brakes system is not properly working. In order to stop truck I must depress brake pedal very hard just to stop truck. Crunching noise every time. Made several trip to mechanic . I changed many part ( brakes) rotors , still and brake vacuum sensor ( purchase from gmc dealer . Still have this problem. Mechanic states, need new vacuum pump. Very dangerous to drive. Very difficult to stop . Please investigate this VIN for common complaints.
brake pedal takes much more effort to push I was parking the car and thankfully was only going about 2 mph because I had to press the brakes with two feet to stop it from hitting the car in front of me. We just arrived from a 2 hour trip and this happened at the end of our trip. Lucky it wasn't on the highway or with a pedestrian in front of me. No injuries
LED Brake Lights fail due to design error typically on both side of the vehicle. I have found multiple reports of a failure on a circuit board that was poorly designed. A copper tracing is very narrow and fractures due to vibration resulting in Brake Light failure. Because the entire module must be replaced the repair costs $800-$900 per side.
NHTSA investigations
Brake Vacuum Pump Failure
On November 20, 2018, the Office of Defects Investigations (ODI) opened PE18-012 to investigate instances of sudden onset of a hard brake pedal that could result in extended stopping distance due to an issue with the brake assist vacuum pump in model year (MY) 2014 through 2016 GMC Sierra 1500 and Chevrolet Silverado 1500 series pickup trucks and MY 2015 through 2016 Cadillac Escalade, Chevrolet Suburban, Chevrolet…
Brake complaints in other Yukon XL years
Frequently asked questions
How common are brake problems on the 2015 GMC Yukon XL?
NHTSA has 64 complaints about the brakes of the 2015 GMC Yukon XL, 21% of the model year's 308 complaints.
Is there a recall for 2015 GMC Yukon XL brake problems?
No. NHTSA lists no brakes recall for the 2015 GMC Yukon XL, though it has 2 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2015 GMC Yukon XL brake problems start?
Half of the complaints with a recorded mileage happened before about 72,000 miles, and 5% before 25,000 miles.
Is it dangerous?
Owners linked 5 crashes, 0 fires and 4 injuries to brakes problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.