2025 GMC Acadia

On October 23, 2026 at about 7:25 AM, while my wife was driving our leased 2025 GMC Acadia (20,773 miles) with our son in the car, the vehicle displayed 'Brake assist failure. Press hard to brake. Speed limited.' The ABS and traction control warning lights came on and the brake pedal became very hard to press due to loss of brake assist. No crash or injuries occurred. This failure matches the eBoost electronic brake control module issue under NHTSA Engineering Analysis EA26006 covering 2024-2026 GMC Acadia. My wife is afraid to drive the vehicle. The vehicle is currently at the dealer for repair. I am requesting that NHTSA record this incident and that GM be required to remedy this safety defect and release us from the lease.

Known GMC problem of a coolant leak which could cause an on-highway failure.

The center console infotainment system is too dim to see during the day leading to distracted driving during daylight hours trying to use it's controls that are very difficult to see especially while driving.

I was driving my car and my brakes felt weird. Then warning lights came on and my car told me that my brakes weren’t working and I would need to push them hard to stop. I put on my hazard lights and turned into a side street and was able to safely stop in the parking lane next to the curb. I shut my car off and then turned it back on. At that point, everything looked normal except for the engine light was on. I started driving again and within less than five minutes, the brakes went out again. I again was able to make it to a side street and stop, but was in a no parking zone. I was able to slowly make it into a parking lot and safely into a spot.

Engine cooling system malfunction, Ive had to receive maintenance on my Acadia 2025 elevation 3 times in the pass 2 months for the same issue, The coolant system. This is becoming a reoccurring issue that needs to be investigated thoroughly. Ive had to get a rental car all 3 times, and this is becoming frustrating and financially draining. My biggest concern is what is to happen once my warranty expires? guess I'll be paying a note and repair cost until a recall is opened on this issue and then will have to wait for reimbursement. This is horrible to say this car was made 2 years ago. Attention is needed on this defective part. I'm so frustrated to I might just trade in this vehicle. I pay for dependability and reliability in the amount of 1300.00 monthly, but only receiving a financial headache.

While driving my 2025 GMC Acadia, the vehicle experienced a sudden and severe failure of the brake master cylinder assembly, causing a significant loss of hydraulic pressure and braking assistance. Multiple dashboard warnings illuminated simultaneously, including ABS and brake system alerts. The brake pedal feel altered abruptly, drastically increasing the required stopping distance and creating an immediate collision hazard. The vehicle is currently grounded at a certified GM dealership awaiting a total replacement of the defective master cylinder assembly under factory warranty. Mileage at the time of failure was 19,000.

Dropping my children off at school, 4 lights came on on the dash. Two messages came across my dash as well. Service esc service abs. EBCM master cylinder needed to be replaced at local GMC dealership.My brakes were failing…This is a known safety issue by GMC and there’s no recall!

I was driving my 2025 GMC Acadia Denali on [XXX] with cruise on. Suddenly sound and banner notifications were telling me that I had no brakes. I immediately hit brake to break cruise and vehicle went faster. I managed to get cruise off from steering wheel. Put flashers on and took foot completely off gas. I was very fortunate that I didn’t hit someone or that no one hit me. After about 2 miles, I was able to pull in an empty church parking lot and get stopped. After getting stopped I was 2.4 miles from [XXX]. I was towed to GMC dealership in Montgomery, AL and diagnosed with defective master cylinder and no brakes. Very concerned because GMC has not issued a recall because the master cylinder failure has occurred many times before. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Since delivery, my 2025 GMC Acadia AT4 has had severe wind noise from the driver's side window at highway speeds. The noise sounds like fingernails on a chalkboard and at times as though the window may shatter. I have taken it to the dealership 4 times with no resolution. I provided video clearly capturing the noise and was still told they could not hear it. I have confirmed the dealer road tests the vehicle in morning traffic at low speeds — where the noise cannot occur. It only happens at highway speeds. Their "cannot duplicate" finding is the result of inadequate testing, not the absence of a defect. After sitting for approximately 7 days, condensation builds up inside the cabin, indicating the driver's side window seal is improperly installed. I reported this to the dealer as well with no fix. After 4 visits, dismissed video evidence, and improper test procedures, the defect remains unrepaired. I request NHTSA investigate this as a potential widespread issue on 2025 GMC Acadia vehicles.

Our onstar module has stopped working since last November after a software update and now issues are starting to cascade causing many other electrical issues to the point that I expect the car to leave my wife and 15 month old daughter stranded. Ours and many other vehicles are having this issue and when any question is asked to gm no response is given or we’re just told to keep waiting.

The contact owns a 2025 GMC Acadia. The contact stated that while driving uphill at an undisclosed speed, the vehicle hesitated, jerked, and stalled. The vehicle was taken to the dealer, where a computer reprogramming was performed; however, the failure persisted. Additionally, the contact stated that while driving 65 MPH and merging into the left lane, the automatic emergency braking system erroneously engaged and the vehicle hard-braked, nearly causing a rear-end crash. The contact immediately depressed the accelerator pedal, and the vehicle accelerated as intended. The contact stated that the failure was intermittent and had occurred approximately six times. The vehicle was taken to the dealer, where the cause of the failure could not be determined; however, the dealer advised the contact that the failure might be related to the camera system. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 3,000.

Today, June 11, 2026, my wife and 9 month old baby were on their way home from running errands in town when the vehicle started to violently shake, becoming frightened my wife tried to apply pressure to the brakes. When she pushed down on the brake pedal nothing happened and the pedal hit the floor. Our brand new 2025 GMC Acadia AT4 had just suffered catastrophic brake failure. So she pulled off onto the side of the road in hopes the uneven terrain would slow her down just enough to put it into park. Luckily enough it did. If it would have been 10 seconds later she would have been on a one way bridge where the speed limit is 60mph with no brakes. Four days prior to today on June 07, 2026 I sent a message to the individual that I bought the car from at the GMC dealership and told him that we had warning lights come up on the dash. He had me try and reset the screen but nothing happened. I asked when we could get it into a shop so it could be looked at he said that he would have someone reach out and schedule a time. I proceeded to ask if we were ok to drive the vehicle until then.To which he responded "If the vehicle isn't giving you issues mechanically, you should be good". Fast forward to today June 11, 2026 my wife is driving and has catastrophic brake failure. The vehicle was then towed by roadside assistance to the GMC dealership.

Telematic Modular Control is not working properly and part is on backorder. Dealership and GMC have refused to put into writing that my vehicle is safe to drive; however, they are refusing rental vehicle while awaiting arrival of part. Several of my safety features are not working correctly, my left turn signal went out randomly and my auto breaking has activated when there has been nothing near my vehicle.

The master cylinder failed under 10,000 miles. I was at 5000 miles. I am reading a lot of people have had issues with the master cylinder in the 2024 early 2025 models. Luckily I was in the driveway barely moving, but man if i were on a highway and it happened it could've been fatal!

When backing out of a parking spot of a store , I went to stop and pressing on the brakes nothing happened and I kept rolling backwards. I looked down to confirm I was pressing the brakes and my foot was on the brake pedal pressed firmly. I rolled to a stop put it in drive and checked the brakes and they worked like normal. I made an appointment at the dealership and had an appointment the next day. The said it did not have any codes, it preformed normal and passed inspected so there was nothing they could do about it.

Brake module malfunction Codes: “service ESC” “break assist failure. Press hard to break. Speed limited”

We filled a report on 04/04/2026 with NHTSA at 12:16 pm but can't find a copy of the whole report. My husband John Chandler was driving our 2025 GMC Avadia Elevation. He was backing out of a parking place when he noticed it wouldn't stop while putting his foot on the break. He was able to put it into drive and it lundged forward and wouldn't stop. He kept pushing with both feet on the break and wouldn't stop. I tried pushing the start button to stop but because his feet were on the break it would restart so then pushed the park button and it stopped as we hit the building. The air bags did not depoy so not going that fast. I pushed the button for 911 and they came on to assist and call police. They asked if everyone was al right and other questions. Lucky no one was hurt and thank God for that. Tow truck was called and taken to local tow yard. The 2025 Acadia was transported to the repair shop but has not been inspected by the insurance company or GMC yet. After repairs are complete it will be taken to the local GMC dealer Ron Smith in Merced, CA for inspection. We did not notice andy warning messages prior to the accident.

I got into my car to leave, I placed my phone on the wireless charging pad. When I got to my location about 10 minutes later, I grabbed my phone and went to put the wrist band attached to my phone around my wrist. The wrist band is a metal chain and it burned me on the side of my wrist and top of hand. I took the wrist band off as fast as I could, then touched it with my fingers to make sure that is where the sting was coming form, and it was. The passenger in the car also confirmed that the wrist band was dangerously hot. I took pictures of the burn marks it left on my wrist and hand.

The contact owns a 2025 GMC Acadia. The contact stated that while driving 70 MPH, the sunlight reflecting off the dashboard chrome onto the windshield was blinding, forcing the driver to use a cardboard to protect their eyes. The contact stated that the failure had been recurring while driving. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The manufacturer was notified of the failure via an online chat. The failure mileage was approximately 10.

I purchased my 2025 GMC Acadia on March 26, 2025. // My vehicle began to have electrical/communication/system issues in August 2025. // I took my vehicle to the dealer to address these issues at this time. When I got to the dealership, a representative performed diagnostics, and said "I can't even get a read on this. There is no signal coming from your module. You need to contact OnStar about this." // I called OnStar, and they ran a test, and stated that it is a manufacturing defect that needed to be handled with GMC. //No one informed me of the severity of the safety implications involved. // In March 2026, my vehicle was inoperable. The module controls everything, and was draining the battery at a severely high rate. I had my vehicle towed to the dealership. They tried to deny all liability and said that they weren't the dealership that sold me the vehicle. // I had my battery jumped so I could take it from the dealership have a new battery installed. My vehicle stalled and shut off while I arrived at the Auto Parts store. *** Answer to Questions: Q1: Yes. My vehicle is available for inspection. It is at the dealership. // Q2: My safety and others were put at risk because the brand new batteries were constantly draining and making me stall out in mid-traffic without having any control. // Q3: Yes. The problem has been confirmed by the dealer. They tried (and still are trying) to avoid responsibility. Other reports show that this is a significant safety issue with many GMC

While backing out of a parking place my husband noticed he couldn't stop the 2025 Acadia and almost hit restraunt behind us, while pusing on the break. He then started to go forward and kept saying "I can't stop it, it won't stop, I'm pushing on the break." The vehicle then went forward and couldn't stop even pushing on the break. I tried pusing the button to turn off the 2025 Acadia a couple times (possible turning back on and because he foot was on the break restarted the vehicle) and then pushed park to see if that would stop. We hit the building in front of us and stopped. The air bags did not deploy so not going that fast. I pushed the button for 911 and they came on to assist and call police and asked if everyone was all right and other questions. Lucky no on was hurt and thank God for that. Tow truck was called and taken to local tow yard.

The vehicle has a serious transmission/drivetrain defect that repeatedly occurs when accelerating from a complete stop, especially onto an incline. The vehicle sometimes does not respond at all when the accelerator is pressed and fails to move, even though acceleration is being requested. In one recent incident, it remained stopped for about one minute before finally responding. During these events, the vehicle jerks and shakes severely and fails to gain speed as expected. This creates a major safety risk at stop signs, intersections, and uphill starts because the vehicle may not move when needed and cannot keep up with traffic. The problem has worsened, and during one of these incidents the check engine light came on. I have video evidence showing the loss of response to accelerator input, severe jerking/shaking, and the check engine light illuminating during the same event. The issue has been reported to dealers and GM customer service but has not been properly resolved.

This is ongoing from the purchase of the car. 1) Infotainment computer screen daytime illumination is so dark as to be a major safety issue as it causes too much time looking away from the road to operate the system. If you wear sunglasses you cannot see the screen at all. The dealer says nothing can be done to improve the problem. 2) Right rear tail light stopped working after 500 miles. Replacement requires dropping the rear bumper and quarter panel. The dealer actually damaged the body of the car while replacing the light. Where are the days of changing out a light bulb? 3) At 1200 miles the transmission torque converter is chattering and slipping on cruise control at 50 MPH. 4) Engine noise is very loud during acceleration. Seats seem flat with no bolsters and little cushioning.

Automatic brake engaged unnecessarily/ unexpectedly while driving forward at a low speed. There was no reason for the brake to engage. There were no objects or people infont of us. This has happened twice in less than a month. Both times we were in a forward motion. It could have been a serious situation if the car behind us had been any closer when we suddenly breaked for no reason.

The vehicle experiences a transmission/drivetrain defect involving delayed gear engagement, hesitation, and apparent slipping. When accelerating from a complete stop (especially onto an incline) the engine RPM increases but the vehicle fails to accelerate as expected. The vehicle jerks and shakes violently and is unable to gain speed. This issue is intermittent but highly repeatable and occurs almost every time when there is a slope immediately after a stop sign. It results in loss of acceleration, violent shaking, and inability to maintain or build speed, creating a serious safety risk in traffic. It first happened around 1 year (early 2026) after the new car purchase (Nov 2025). There are no warning lights or messages. The dealer claimed they were unable to reproduce the issue during a brief test drive without me present and incorrectly attributed it to a bulletin without performing a detailed diagnosis or repair or looking at the video we recorded on the issue. The issue persists and affects safe operation of the vehicle. No inspection has been done by police or insurance. In one instance, this occurred while other vehicles were approaching from behind, creating a dangerous situation where I could not accelerate to match traffic flow. This resulted in a high risk of being rear-ended due to the unexpected loss of acceleration. I am aware of other consumer reports describing similar transmission-related symptoms such as slipping, hard shifting, and hesitation in this model.

The contact owns a 2025 GMC Acadia. The contact stated that while driving 35 MPH at nighttime, there was an abnormally loud explosion and the contact became aware that the sunroof had exploded unexpectedly, causing shattered glass to fall inside the vehicle onto the contact's head, face, and body. The contact stated that two of her children were occupying the third-row seats when the failure occurred. The contact stated that a larger quantity of shattered glass fell near or in the car seat of the contact's son, who was not occupying the vehicle during the failure. There was no reported injury. The vehicle was taken to the dealer, where the contact was informed that the sunroof needed to be replaced; however, the repair was not covered under warranty. The contact was referred to the insurance company for assistance. The dealer informed the contact that an engineering inspection had been requested. The vehicle was not yet repaired. The manufacturer was contacted and informed that the vehicle could be repaired under warranty at the discretion of the dealer. The failure mileage was approximately 9,000.

Unknown. Brakes still squeaking after getting them changed with the bulletin notice. Engine surges and idles rough- dealership could not diagnose. Not accelerating randomly, pedal goes in and it does not engage. Gas tank not filling up all the way. Rear cross tracking warning turned off when it is not turned off. AC smells rotten and musty

2/10/26. Driving down the highway behind a truck and horse trailer at 60 mph, electric brake system stopped working, couldn't stop, a turn lane saved me from rear ending the horse trailer. I thought i was going to die and kill or injure animals and people in my path. Police came and tow truck. 2/10/26 Vehicle was towed to the closest GMC dealer. MERIT GMC Duncan, Ok Vehicle is at service department. There has been 3 events of complete power failure with the vehicle. It had to be towed three times before. All within the last 6 months. It had never happened while driving! When it happened, a brake light appeared on my dash with the message "electric brake failure" and "speed limited". I slammed the Brake pedal to the floor repeatedly with nothing happening. I had many emotional breakdowns to the police officer, at the dealership, at work when I finally got there hours later and am terrified to drive again. I could have died and hurt others.

Warning message appeared stating "service brake assist" and "service ESC". Took vehicle to dealer, they found faulty Master Cylinder. Multiple parts involved, some on back order, could take weeks to a month or more for repair. Vehicle is less than 1 year in service with approx. 6k miles.

OnStar/Telematics Module cuts out, rending GPS and OnStar functions useless

I bought this vehicle in August 2025 and October was the first incident that this occurred. What happened was I was driving to pick up my husband and all the warning lights on my car dash started going off and then it died. After we got it started again we took it to the nearest GM dealership and after we parked, we could not get it to shut off then when we started driving again, it died in their parking lot. This has happened multiple times since.

New vehicle. At 935 miles on odometer, displayed “Service Power Steering” “No Assist Soon” message on dash. Contacted OnStar and was advised of potential loss of power steering & advised to take car to dealership. Car spent 10 days in service to have a new steering gear installed at GMC dealership.

Approximately 2 months after purchase, the sunroof spontaneously shattered/exploded while driving on the interstate. We had it fixed and about 3 months after that, the same exact thing happened.

The antenna fin cover came off while driving down the road. I had been a possession of the car less than six weeks. I’ve contacted the dealership- it’s covered under warranty, but the part is backordered because it’s such an issue.

I accidentally ran out of gas and my car died directly underneath a railroad crossing arm. I had been stopped to allow an Amtrak train to go by and my car died when I started to move forward after it passed. Thankfully I wasn't on the tracks, but I was close to them. I immediately got out of my car and the woman behind me said she would help push me out of the way of the crossing arm. I went to put my car in neutral, something I do weekly when I go through the car wash, but my dash kept saying "conditions not correct for shift". I tried repeatedly and it would not allow me to put the car in neutral because I couldn't fully turn it on. I did a quick search online and found there was no information on how to get it into neutral if the car is dead. My battery was still working and my car was in accessory while I was trying to change gears. I had to call 911 and they had to reach out to BNSF to alert incoming trains. It was an ordeal. I spotted a tree removal company across the street and they had a can of gas for me to use. I was able to partially fill my tank and then drive across the tracks before a train came. Afterwards I called the dealer and we discovered together that there is no backup safety feature that allows a disabled car to be put into neutral. The dealer was just as surprised as me. This seems like an obvious safety issue if a car is to break down on train tracks, the middle of the freeway, or in an intersection. I don't understand why it is allowed and why dealer

I was driving on a two-lane road when unexpectedly my front moonroof spontaneously shattered sending glass down on top of me, the console area, and the passenger and rear seating areas of my 2025 GMC Acadia. It happened without warning and no external factors. It was a pleasant sunny November day. The moonroof was not open at the time. Fortunately no one else was in the vehicle with me at the time and no other cars were nearby since the two-lane is not a heavy traffic area. This put my safety at risk and could have put others at risk had others been in the vehicle or nearby since I was startled and had the natural reaction of crouching over and down in an attempt to protect myself therefore taking my eyes off the road and not paying enough attention to driving the vehicle. Glass could have fallen and hurt other passengers. The remaining moonroof glass crackled and I then looked up in shock wondering what happened and then feared glass fall into my eyes and immediately looked down away from the moonroof. I had just left my residence before the incident and was less than two miles from home. I found the next available place to turn around and drive back to my home and exit the vehicle. I then called the dealership I bought the vehicle from in January 2025, new. I also called GM Customer Service to seek assistance. The vehicle has 7125 miles. There were no warning signs. The incident happened today and no one has inspected the vehicle and its damage. A customer service case was

I purchased this 2025 GMC Acadia on 3/29/2025. About a week into owning it, the navigation stopped working. OnStar was able to reset my system. Then, about a month later, the vehicle locked my keys in the cabin without my knowledge. OnStar was able to unlock my vehicle remotely. Then, on 10/23/2025, I noticed my navigation was not showing my true location. I tried the Google Assistant, and it wasn't connected. After further investigation, my wifi hotspot was not working either, along with other connectivity apps. I researched how to manually reset my system and followed all prompts; that did not fix the problem. I pressed the OnStar button, and nothing happened; no connection. I thought that maybe the vehicle needed to cycle a few times. I let this continue for about a week before calling OnStar from my phone. They told me to press my SOS button; if it didn't connect, then I would need to take the vehicle to the dealership. So I took it to the dealership 11/6/25. They tried to download the update to my vehicle multiple times, over 6 hours at the shop, and the vehicle wouldn't accept the update. It is determined that the OnStar telematics control module is defective. The dealership says the part is backordered, and they do not have an ETA for arrival. After perusing the GM/OnStar forums, I am seeing that this is a repeated issue for many customers on vehicles as old as 2018, and the part doesn't come for 6 months or more in most cases. It does seem more prevalent with vehicles

Brakes have failed now three separate times. The brake pedal becomes firm and the car will not stop or slow at all. I am pregnant and also had my toddler in the car with me. No warning symbols on the dash. Taken to dealership after several weeks of communication saying this was a safety issue and received a loaner vehicle. However, they have said if THEY cannot reproduce the issue, we will just get our car back. This is unacceptable. This is one of five issues we have already had with this vehicle.

While driving vehicle, multiple warning codes appeared including: service traction control, ABS, service brake system and others. More importantly, the power brakes failed and a code was thrown to press hard on brakes to stop vehicle.

I have the little feature that will brake for me if it thinks ima get in a wreck. However it’s glitchy!! I can be the only vehicle on road in BOTH directions, cruise set at 60 when out of nowhere the car slams on the breaks. We go down to like 52 then like nothing ever happened we are back to 60. This has happened several times. I have brought the car into my dealership tomorrow have the software updated and the camera recalibrated. Even after these steps were made this issue is still occurring. Happens about one to two times a week, so pretty often. My worries that I will be rear ended one day if this is not corrected.

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 failure. I have not received any invoices or paperwork to send you at this point. All I can upload is a video of the warning lights that were appearing on the dashboard after the incident.

While driving my 2025 GMC Acadia Denali on [XXX], from Omaha, NE, to Laurie, MO, I received a "Service Brake Assist" warning lamp as well as "Check Engine" and "ABS" warning lamps in St. Joseph, MO. At this point, my vehicle had 6,945 miles on it. We turned around and went back to Omaha. We dropped the car with Gregg Young Chevrolet at 7,095 miles. The dealership identified the issue as EBCM and master cylinder assembly failure. It replaced the EBCM and master cylinder assembly, test drove the car 7 miles and told me my Acadia was ready to go. I did not make it out of the dealership parking lot before the "Service Brake Assist" and "Check Engine" lights came on again. The dealership again identified master cylinder assembly failure, again replaced said assembly, test drove it 10 miles this time and told me my Acadia was ready to go. I got my Acadia and made it 1.1 miles before the "Service Brake Assist" light again came on. I promptly returned my Acadia to the dealership, where it sits today. At the date I am typing this (9/14/25), the dealership has had my Acadia since 8/22/25. The master cylinder has now failed 3 times at this point. First, after 6,945 miles, second after 7 miles, third after 11 miles. The safety of myself and my family was put at risk by the potential failure of my brake system. This should not happen on a brand new car with less than 7K miles and darn sure not 3 times in a row! Yes, the problem has been confirmed by the dealer 3 times. The dealership is n

Bought new 2025 GMC Acadia in March of same year. At ~4500 miles I started getting Brake Assist, Forward Collision and Electronic Stability Control warning messages on dash. Upon researching, this is an increasingly common issue with this vehicle that can render the brakes unusable. I no longer feel safe in the vehicle and want it refunded. Car is now in the shop. Taken in on 9/11. Problem has been confirmed by dealer.

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 and reservoir. At that time, I was told the ETA was unknown and I have been calling back every week. On August 23rd I filed a complaint with GMC and have struggled to get anywhere with them. They tell me the dealer has the parts and the dealer tells me that they do not. I still have no ETA and it has been officially 2 months without a car. I am told that it is not safe to drive. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Brake assist warning message and BRAKE light appeared a couple of weeks ago, along with others. Brought the car into the dealer, who initially thought they cleared the errors and reported no additional issues when they ran the diagnostics. Nothing was cleared. Vehicle application and monitor also does not show an issue, even though the warning appears at each start up and none of the related safety systems work (ABS, ESC, AEB, etc.) that rely on the brake pump. Information from the dealer and owners manual are in conflict, with the dealer allowing me to drive while the owner's manual indicates it should not be driven with the BRAKE light lit. They have now "diagnosed" a "failed" master cylinder unit that includes electronics and the pump. The car had about 4500 miles on it when the issue occurred. I am at a loss for if it should be driven and trusted or not.

Bought car brand new at 427 miles car started bucking shaking pulsating while driving bought to brennen gmc plattsburgh ny at 811 mile did same thing but worse brought back to dealership they put camshaft actuater and solenoid in at 6041 mile car was motor started knocking stalling controlable in traffic back at shop

Purchase vehicle on August 13, 2025 with 27 miles on it. Drove home from dealership. Started the car on Friday morning and all of these warning lights appeared - Electronic Stability Control, Brake Assist Service, Brake light indicator, ABS indicator, traction control indicator, collision warning indicator. Car only had 69 miles at the time. Took vehicle to dealership on August 18, 2025. After diagnostics were performed, it was determined that the Master Brake Cylinder is the issue. The part is on back order and there is no estimated time of when the part will be received and installed. Dealership Rep told me that it was safe to drive the vehicle to the dealership. Service Technician then explained to me that I should not be driving the vehicle.

I purchased the vehicle, and twelve days later while operating the vehicle I experienced full braking power failure. My foot was to the floor board while trying to get the car to slow down. Up until the point of brake failure, there were no warning lights or "symptoms" that would alert me as to an impending problem. My young child was also in the car so that was extremely scary also. During this time, the "service brake assist" light and ABS light came on. I was able to slow the car down enough, restart the car, and the brakes seemed to work, however all of the related braking lights were on my dash. It was brought to the dealer the next day. The dealer has noted that its the master cylinder that needs to be replaced. However, they replaced it, and the new master cylinder has also failed, so they'll need to try and replace it again. I'm concerned this issue could cause severe accidents in the future if it continues to not be addressed.

Upon starting the vehicle the vehicle immediately starting moving while foot on brake and moved from park to reverse or drive. Unable to stop the vehicle in idle gear and no gas pedal applied. Power steering warning and no brake assist warning on the dash. Unable to stop vehicle within 20ft while traveling at idle speed. Vehicle lights and warnings have been reproduced and is currently at a dealership awaiting further inspection. Vehicle is available for third party inspection if needed. Vehicle at Barker Buick GMC, 6444 W Main St, Houma, LA 70360 on 8/4/25

Around 7k miles on the vechicle, driving down the road it kept coming to a stop and skipping. Pulled into the parking lot the best that I could and put it into park. After it wouldn't shift into anything. Never gave any dash signals. It is currently in the shop getting a whole new transmission.