2025 GMC ACADIA Forward Collision Avoidance Automatic Emergency Braking Problems

We had complete brake system failure while driving the car on the highway. The brakes went all the way to the floor when applied and we came inches going into fast moving oncoming traffic before the vehicle stopped. I had to push the break with both feet with all the strength I had to get the brakes to respond at all. The brake assist failure warning light came on and another warning light came on that said SERVICE ESC. I have this on video. This was the first time the warning lights have ever come on. It’s a brand new 2025 car with only 800 miles on it. We were advised by the dealership who sold us the car to get OnStar to tow the vehicle to our local GMC dealership where we bought the car. When the car was hooked up to the diagnoses machine it said brake system...

I purchased the car on [XXX]. Drove the car about 8000 miles and then all of a sudden the dash lights all lit up for the brakes, ABS, traction control. I pulled the car over and turned it off. When I restarted my car, the lights continued to stay on and it told me to service immediately. I called my dealer and they could not get me in within 2 weeks so I took it to another local GMC dealer who could get it in to look at it that week. I took it in on July 9th, and then received a called a couple days later telling me that it had a bad Brake control module that they needed to order. A week later was told the part was on backorder. Two weeks later was told the part came in but it was still missing the brake master cylinder...

dash lit up with ABS, traction control, and ESC warnings. Technician stated the entire brake system needed to be rebuilt. There is currently no ETA on when the parts to be able to accomplish this will be available.

At startup today vehicle displayed “Brake Assist Failure. Press Hard to brake. Speed limited.” It also displayed “service.” It also displayed “ESC,” and the word “service. An internet search indicated this may be a common problem of this vehicle, caused either by a software error in the Electronic Brake Control Module, or due to a defective brake master cylinder. There is a GM service notice for these defects, N242471431. Regardless of the cause, the brake is extremely mushy, and requires a high degree of force to stop the vehicle. GM says there is no recall due to this defect. This is a brand new vehicle and therefore it must be a defect in the vehicle. Given that braking is a fundamental safety issue, it’s hard to believe there is no recall already issued.

At approximately 4900 miles, the brake master cylinder failed on my vehicle. It has been at the dealership for over a month awaiting parts for repair.

Multiple brake warning lights came on while driving vehicle

Car driven off the lot 06/14/2025 On Sunday 07/06/25 (21 days from purchase) while driving home from a 30 minutes away from home trip with 3 young children with me, the car gave multiple alerts and service warnings. "Service Brake Assist" and "Service ECS" Lights / Symbols related to the following were also displayed: Traction Control System (TCS)/ Electronic Control Stability Light, Anti-lock Brakey System (ABS); Brake System Warning Light, Forward Collision Alert and BREAK light I stopped the car immediately and pulled to the side of the road. After restarting vehicle, lights were still displayed and service alerts still on. Power steering was very diminished and the breaks were struggle to break. Acceleration was also impacted and every time I breaked it appeared as though the car was trying to accelerate. I was able to drive the car home slowly following back roads. On Monday 07/07/25 I called the...

ABS, EBCM, Traction Control and brake lights on.

After having my 2025 GMC Acadia Elevation for 2 weeks, I turned it on and six lights on the dash lit up. ESC, ABS, Tractions Control and more. I was leaving a store at the time this happened and drove home. Also, my cruise control would no longer work. Took my Acadia to the dealership the following business day to be serviced, only to be told a week later that the master brake cylinder needed replaced. This part of course was on back order. My new part arrived two weeks later, only to discover that two additional one-time parts (seal and reservoir) are now needed. These parts are also on back order with an estimated ship date of mid to late July.

The ESC, ABS, and Traction Control, Yellow warning lights, BRAKE, Red Warning light. Diagnosis is ABS, module, and master brake cylinder bad 2025 GMC Acadia Denali, 1150 miles. No parts available because these are all needing work! People are having near misses and collisions due to this problem! Put a stop production order until these are fixed!