2021 GMC Acadia Driver assistance Problems

My thermostat failed in my car, my temp goes out and reads at 0° then my steering assist says it’s reduced. There are many forums online regarding this issue.

NHTSA ID

11740094

Incident

Feb 15, 2025

On March 27, 2026, I experienced a complete brake failure while driving a 2021 GMC Acadia in a school zone at approximately 3:00 PM. When I pressed the brake pedal, the vehicle did not respond. I attempted multiple times, including using the emergency brake, which did not activate immediately. The vehicle remained in motion for several minutes in an area with children and parents present. The emergency brake only engaged after approximately 30–45 seconds of repeated attempts. I was forced to steer off the road to avoid a collision. The vehicle had been inspected at a GM dealership on March 16, 2026, just eleven days prior, where the brake system was evaluated and no issues were identified. After the incident, the dealership diagnosed a leaking vacuum pump, which is a component that supports the brake booster system. This failure occurred without warning and created a dangerous situation. I am concerned this may indicate a broader safety defect.

NHTSA ID

11728151

Incident

Mar 27, 2026

The electronic dashboard goes black while driving. I was driving to work on the highway at highway speeds and the entire electronic dashboard went black including the hud display and the radio screen. The radio screen turned back on and auto reconnected to my phone and android auto. I was able to safely get to an exit and park, turn off the car and restart and the dash did come back on to then go black about 5 minutes later this time the hud stayed on and I was able to get to work where the car sat off for 8 hrs , when leaving work the dash stayed on. The radio screen would turn off randomly and unable to connect to a programmed cell phone via Bluetooth or data cable. I brought the vehicle in for a service and this issue plus the concern of the transmission shuddering. The dealership found the problem and both the dashboard and radio needed service updates and both were charged to fix. A service update should not be charged for the dash as you have no speedometer when it goes out. There was no warning or alert that the dash or radio needed an update.

NHTSA ID

11709819

Incident

Aug 24, 2025

Cars is not keeping track of temperature showing engine is cold after 30 minutes of driving, fan runs for extended periods of time after shutting off, check engine light comes on, steering assist alert comes in screen. All of this happens in a cycle. To stop it the battery has to be unplugged and reconnected resetting the car and everything goes back to being fine for a short period of time.

NHTSA ID

11709573

Incident

Jan 1, 2025

For the 3rd time of ownership the cooling fan stays on after vehicle is turned off and the display “steering assist is reduced, drive with caution”.

NHTSA ID

11701173

Incident

Nov 23, 2025

Instrument cluster malfunction. Entire instrument cluster blacking out every 60 seconds, then rebooting nonstop while driving. While this was occurring, none of the advanced driver assistance systems functioned, nor did the speedometer or other gauges. This occurred while on a trip, and meant having to travel a long distance without having emergency braking, collision warnings or the ability to monitor speed. The car was taken to local dealer and they replaced the entire instrument cluster.

NHTSA ID

11679159

Incident

Jul 14, 2025

The Vacuum pump on my 2021 GMC Acadia failed causing my breaks malfunction. This Problem was confirmed by a certified mechanic that repaired it. this is in conjunction with the NHTSA recall issued under N192268490.

NHTSA ID

11670283

Incident

Jun 28, 2025

Vehicle gives, “Driver assist reduced Drive with care” warning randomly. Lane change will no longer work and engine light will come on. Problem is sporadic and does not stay active. Engine light will shut off after a day. Once vehicle is shut off cooling fan runs extremely loud and for a long period of time draining battery.

NHTSA ID

11650976

Incident

Mar 11, 2025

The contact owns a 2021 GMC Acadia. The contact stated while attempting to park the vehicle, the contact became aware that the front and rear-view cameras were inoperable. The camera failure message was displayed. The contact stated that the cameras failed to function properly, and an image was not displayed. The dealer was contacted. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 40,000.

NHTSA ID

11645263

Incident

Feb 27, 2025

Mileage

40,000 mi

The contact owns a 2021 GMC Acadia. The contact stated while driving 50 MPH, the vehicle suddenly decelerated to 35 MPH. The vehicle stalled, and the "Steering Assistance Reduced" message was displayed. The vehicle was restarted. The vehicle was taken to the local dealer the following day, where it was diagnosed that the accelerator pedal and terminal connector were bent. The dealer retrieved DTC codes: P2138, and P2122. The vehicle was repaired. The manufacturer was notified of the failure. The approximate failure mileage was 27,792.

NHTSA ID

11616263

Incident

Jul 28, 2024

Mileage

27,792 mi

The rear view camera was supposed to have been fixed during the safety recall in 2022, but two years later and over seven visits to dealership service repair shop, it still has not been fixed. GMC says they don't know how to fix it because they have tried everything and that because my warranty has been "out" one month - there is nothing they can do for me. My back up camera has not worked since the recall repair. What can I do? The car has been in the shop, who says they are contacting GMC Service Expert - but they are not communicating with me anymore. I have no car and no fix.

NHTSA ID

11586651

Incident

Feb 28, 2022

My vehicle stops working while in traffic when the auto stop is engaged. The abs, parking brake, and dash flashes prior to the engine stopping. I have been to the dealership multiple times and they are never able to recreate the issue. The check engine light codes produced are P0014 and c0800-03.

NHTSA ID

11574872

Incident

Mar 1, 2024

The contact owns a 2021 GMC Acadia. The contact stated that while reversing, the back-over prevention camera failed to display an image. The vehicle was taken to the local dealer who diagnosed that the back-over prevention camera was faulty and needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure and informed the contact that the VIN was not included in NHTSA Campaign Number: 22V709000 (Back Over Prevention). The contact stated that the vehicle had experienced the failure listed in the recall. The failure mileage was 25,000.

NHTSA ID

11567287

Incident

Jan 1, 2024

Mileage

25,000 mi

The contact owns a 2021 GMC Acadia. The contact stated that the software update was performed under NHTSA Campaign Number: 22V709000 (Back Over Prevention). After the software was updated, the Lane Departure Assist system failed and was no longer alerting the driver when the vehicle was drifting into the other lane. The vehicle was taken back to the dealer who completed the software update however, the cause of the failure was undetermined. The vehicle had not been repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 17,700.

NHTSA ID

11546941

Incident

May 27, 2023

Mileage

17,700 mi

While driving down a busy road automatic braking engaged for no reason causing the Acadia to abruptly come to a dead stop in the middle of the road with nothing in front of me. Red collision lights came on at the same time as braking with no prior warnings. Could not get the car to move for a few minutes (when giving gas there were grinding sounds) then the braking system let up. Drove for another few minutes and it did it again. Called GM and WE had to figure out how to get the car to the dealership with a major safety issue. Took the car in and it was throwing B390F, U0184, B395A codes. When we received the vehicle back one of the codes was for a bad back up camera so the new rear back up camera view is so stretched you can’t use it to back up nor does it have the lines anymore. The rear view camera now has a view that is sideways. So I took the car back to the dealership and they had no clue how either could be happening and would look into it again. Did my own research and figured out there are two cameras on the tailgate so the rear view camera was reinstalled wrong. Sent proof of how I came to the conclusion and that I wanted the backup camera replaced/fixed also. Its been over a month and I cannot get my car fixed because I refuse to pay for a rental on something they messed up because they have no loaners. Well on 11/14/2022 my cars automatic braking system activated again only this time it stopped in the middle of the road and was not as dramatic as last time. The warning lights came on as the car was coming to a stop. This time I was able to move shortly after it came to a complete stop. GM dealership wants me to bring the car in somehow and I will be carless for who knows how long. There is also a safety recall for a cable for the backup camera with no parts available. I have an RO number and a complaint number.

NHTSA ID

11493594

Incident

Sep 22, 2022

We purchased the vehicle in March 2021 and within a few weeks, the rear camera started working intermittently. At one point, it displayed a black screen with a red warning triangle. The dealership ultimately replaced the camera and we haven't had the problem since.

NHTSA ID

11487101

Incident

Apr 1, 2021

As I was stopped in line behind a car at the ATM, my foot slipped from the brake, I quickly placed it back only to find that I ended up going forward. I quickly moved my foot more to the left for the brake only to end up going forward even faster hitting the car in front of me. I then put my left foot firmly on the brake. Now with both feet on the brake the car is climbing up the car in front of me and not braking. Finally, I put it in park and cut the engine. The whole front end of my car is crushed. Now 5 days earlier my husband had a similar incident when he was parking the car and thankfully only hitting the curb. Looking at the brake pedal you will find that there is a rubber edge hanging down on the right side. IF YOUR FOOT SLIPS BELOW IT while crossing from the accelerator going right to left, YOU WILL NOT hit the brake but will continue to press the accelerator. In fact, if you raise your foot upward, you will only raise the brake. The only way to get to the brake is to get out from under it by going toward the accelerator and then back to the left. This action does not work in an emergency! I believe this rubber edge is too large is a safety hazard. We are still in the process of assessment by insurance, body shop and GMC.

NHTSA ID

11481608

Incident

Aug 27, 2022

While driving through intersection auto braking system activated for no apparent reason . Could have caused a crash due to sudden unexpected braking. No warning lights or alarm noted during or after event. Dealership was unable to find any problems with the automatic braking system.

NHTSA ID

11466848

Incident

Feb 22, 2022

I got into an accident because my back up crap camera did not warn me that a car had turned behind me. Also when and backing up and a car is coming it doesn’t indicate the car is coming until it’s behind me. I’ve taken it to the dealer and they say there’s nothing wrong with it. Also there is no break when you come too close to something in front of you.

NHTSA ID

11463901

Incident

Dec 4, 2021

Brand new vehicle purchased from dealer, at 8900 miles transmission slipped. Dealer has for 2 hours and couldn’t find problem, but replaced transmission fluid it was dark. At 9000 it happened again, they have vehicle and said the new transmission fluid is dark and muddy. Only 100 miles, so they determined they need to take apart transmission and see what happened. It’s a 52k car, it should not be repairs, it should be replaced under warranty. Video of 8900 from dealership https://video.37483.net/timeline/2CJTHEW6

NHTSA ID

11450038

Incident

Jan 31, 2022

Since purchase of this vehicle in Dec 2020, the rear camera vision has been intermittent. I originally thought it to be driver problem however I am now told that there is a module that needs to be replaced and it is not available and possibly not being manufactured at the present time. As a result the entire Camera parking assist system is completely out of service with no information on when the module may be available to repair the issue. I believe this may be a Safety issue as backing up into traffic be it parking lots or roadways, this equipment is an essential addition to safety to other vehicles and pedestrians.

NHTSA ID

11429267

Incident

Jan 15, 2021

The contact owns a 2021 GMC Acadia. The contact stated that while his wife was reversing the vehicle, the accelerator pedal was stuck to the floorboard and the vehicle crashed into the garage wall. No medical attention was received. No police report was filed. The dealer was made aware of the failure and informed the contact to tow the vehicle to their location to diagnose the failure. The vehicle was awaiting a tow truck and had not been diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 2,500.

NHTSA ID

11427862

Incident

Aug 5, 2021

Mileage

2,500 mi

Was on the interstate driving when the emergency brake engaged causing the car skid the tires and almost completely coming to a stop in heavy traffic. Shortly after this the transmission had issues which caused the car to be undrivable and had to be towed. The dealership had the car for over a month and replaced the TCM. There were no other warnings prior to this.

NHTSA ID

11418857

Incident

Apr 9, 2021

VEHICLE PURCHASED NEW MID-MARCH 2021 AND IN LESS THAN 30 DAYS THE REAR BACK-UP CAMERA STOPPED WORKING INTERMITTENTLY. THIS HAS OCCURRED SEVERAL TIMES AND THE VEHICLE IS CURRENTLY AT THE DEALER BEING DIAGNOSED.

NHTSA ID

11415501

Incident

Apr 7, 2021

Mileage

500 mi