What 977 owners told NHTSA about the 2015 GMC Yukon Denali Xl 1500

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. The contact was advised that the failure was possibly related to NHTSA Campaign Number: 19V645000 (Service Brakes, Hydraulic); however, the VIN was not included in the recall, and there was no warranty coverage on the vehicle for the failure. Additionally, the check engine warning light was illuminated. The vehicle was not diagnosed or repaired due to the cost. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 143,000.

NHTSA ODI 11726283

The contact owns a 2015 GMC Yukon. The contact stated that while depressing the brake pedal, added pressure was needed before the vehicle came to a stop. The contact stated that the vehicle hesitated or jumped before coming to a stop. Additionally, the contact stated the transmission was slipping. The contact stated that while driving at various speeds, the vehicle stalled before self-correcting. The contact also stated that while idling at a stop light and attempting to accelerate, the vehicle hesitated, but gradually accelerated as needed. The contact stated that the rear taillight intermittently failed to illuminate. The contact stated that the check engine warning light was illuminated. The transmission fluid was flushed; however, the failure recurred. The vehicle was taken to the dealer who diagnosed the vehicle and determined that the transmission was fractured, and the light bulbs needed to be replaced. The transmission was not repaired or replaced. The headlights were not replaced. The dealer confirmed that the brakes were included in NHTSA Campaign Number 19V645000 (Service Brake, Hydraulic) and the vehicle was repaired; however, the failure persisted. The vehicle was driven to the residence without further repairs. The contact stated that the vehicle had become inoperable. The manufacturer was not informed of the failure. The failure mileage was approximately 195,846.

NHTSA ODI 11666325

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.

NHTSA ODI 11665834

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

NHTSA ODI 11663384

Brake vacuum pump faulty again.

NHTSA ODI 11650130

The contact owns a 2015 GMC Yukon. The contact stated while driving 5 MPH, the brake pedal was depressed, but the vehicle failed to stop as intended. The brake warning light was illuminated. The contact stated that the brake pedal was depressed to the floorboard. The vehicle was slowly driven to the dealer; however, no cause for the failure was found. The vehicle was not repaired. The contact stated that the failure persisted. The contact associated the failure with NHTSA Campaign Number: 19V645000 (SERVICE BRAKES, HYDRAULIC). The manufacturer was not made aware of the failure. The failure mileage was approximately 90,000.

NHTSA ODI 11644215

Trailer braking system warning is incessantly going off, without cause. Extremely distracting. No way to stop it. Truck has never even towed / trailored anything. Has happened multiple times over the last 6 months. Today occurred 26 times during driving

NHTSA ODI 11629459

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.

NHTSA ODI 11628866

There has always been break problems with this vehicle. Some recalls have been done. Now there is a new problem, I took it to the dealership. There is a special coverage to fix this issue. GM denied to fix it because the special coverage expired on 06/06/2024. But the vehicle is under the miles and the problem just started.

NHTSA ODI 11627708

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.

NHTSA ODI 11627260

Loss of power steering, loss of abs, loss of cruise control, loss of forward crash assist, loss of lane departure, lose of side detection, oil leak from oil cooler line connection leaking down engine, potential fire, parking sensor, arm rest phone charger short circuit potential fire, wires pinched off at hinge point of center counsel, trailer brake system, stabilitrac, all current errors make vehicle unsafe to drive, ongoing issues since purchase including service reports of the same issues from previous owner

NHTSA ODI 11620757

Defective wire harness between 2 body control modules, causing alarm to go off repeatedly "Service Trailer Brake System" and also "Stabilitrack" will come on randomly and lock my brakes up and all of the features in my dash. This has been very scary to drive and has brought the vehicle close to collision more than a handful of times now.

NHTSA ODI 11618127

I keep getting a warning on my display on dash about my trailer brake system is not working. Also my temperature gauge stops working and I have to take off negative cable on battery to reset it. Temperature control sensor has been replaced but the problem still continues to happen.

NHTSA ODI 11617294

The brakes are hard to push to come to a stop. I brought it to a mechanic and he said it was my vacuum pump. The air bag light comes on when you hit a hard bump in the road.

NHTSA ODI 11605247

While I’m parked or even driving I keep getting a alert on my speedometer ( Trailer Break System ) and it’s not a 1 time alert the whole time I’m driving it’s constantly alerting me yet I don’t even use my Trailer system at all, it’s concerning due to the distraction of trying to clear the screen constantly while I’m on the high way.

NHTSA ODI 11596831

My 5 children and I experience a traumatic experience in afternoon traffic as my 2015 GMC Yukon failed to pick up speed while waiting to make a left turn at a traffic light. The vehicle - no matter how hard I pressed on the gas didn't accelerate immediately which almost cost an accident. The vehicle rode smoothly for a few minutes then out of nowhere - it started jerking and stuttering bad for 15 seconds or so then would go back to riding smooth. When pressing the brakes - it seems to "lock" to a certain extent, so I have to press really hard on the brake to slow down/stop the vehicle sometimes makes a strange noise when doing so. I took the vehicle to be accessed by a service center in my area - it was at that time that I was told that my vehicle issues are known common GMC issues in these vehicles & more unfortunately. It's unfair to be penalized with an expensive transmission repair when these issues are known to the manufacture but not the consumer - despite being "VIN specific" as told by GMC customer service. This vehicle is needed as it is utilized to transport my children however, it's unsafe at & parked in my driveway. I was directed to reach out to GMC for remedy of the identified issues.

NHTSA ODI 11587258

On several occasions, have noticed the brakes failed to operate properly when vehicle is at low speed. The pedal becomes extremely hard to push and there is almost no braking power. This has occurred in stop and go traffic and nearly caused an accident.

NHTSA ODI 11581577

My breaks stop working in drive through, pulling in parking spots, backing out, slow speed of traffic. I found out it's the power break vacuum pump. It then says Service brakes on my dash when it occurs. This started about 2 weeks ago.

NHTSA ODI 11567622

I have owned this vehicle almost 6 years, 40,000 when purchased used. Since purchase, we have had multiple issues with the trailer brake system randomly going off, dinging non stop, we had the problem serviced under our warranty and is now going off again. We do not tow but a few times every summer which is our jet skis however. This has happened multiple times prior to us using our warranty, the garage says they fix it but it keeps happening. I am very frustrated that I can't drive my vehicle down the road without a continues dinging. I looked up what "trailer brake system" means and found that it can be very dangerous and GMC's are known to have this problem, it is suggested that I lodge a complaint in hopes of getting this problem resolved from the manufacturer before a driver becomes seriously injured when the braking system decides to fail. I have read complaint after complaint. My warranty is now expired as I recently rolled over 100,000 miles, the GMC garage told me the part was around $78 but over $400 with install, ridiculous! I have already replaced this part a little over a year ago, I went to the garage where the warranty work was performed and got all the paperwork. Why has this problem not been categorized as a recall at this point? Something isn't right!

NHTSA ODI 11538370

“Service Trailer Brake System” indicator light and alert continue happening. As of this weekend, my rear driver side taillight has begun going in and out/off and on.

NHTSA ODI 11530471

Trailer brake service malfunction

NHTSA ODI 11523898

Brake vacuum repair. Could not stop vehicle. Brakes would get hard and vehicle kept moving.

NHTSA ODI 11502097

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

NHTSA ODI 11496505

My vehicle Has a Service Trailer Brake System notification in my dash that dings as well. It does it on cold mornings with no trailer attached. I don’t trailer often.

NHTSA ODI 11495487

My brakes went out and a “service” message came up and said “brake assist”

NHTSA ODI 11487809