2021 Gmc Acadia

My brake pedal got stiff when I was driving. I had zero control of my brakes. I was informed by a GMC dealership that my BRAKE BOOSTER blew up causing my brakes to stop working and metal shrapnel to be sent into my engine. My 2021 vehicle is a complete loss. GMC has done NOTHING to help me.

The contact owns a 2021 GMC Acadia. The contact stated that while driving at various speeds, the vehicle was unintendedly drifting to the right. The vehicle was taken to Dally Tire Company, where it was diagnosed with rear links failure and misalignment. The vehicle was not repaired. The vehicle was taken to the dealer, and the contact was informed that the VIN was not under recall. The dealer scheduled an appointment and provided an estimate for the repair. The manufacturer was not yet contacted. The failure mileage was approximately 42,200.

I was driving and all of a sudden my break pedal was inoperable. It was stiff and unable to be used. Luckily I was only going 40 MPH. I pulled into a parking lot and my car started shaking and apparently the metal parts from the vacuum pump blew into my engine, which completely wrecked my engine. I nearly could have died and now my 2021 car is completely destroyed.

Display suddenly says "Steering assistance reduced, drive with care" Temp gauge goes to C and stays there. Radiator fans speed up and stay on after the car has been turned off. Dealer unable to find a diagnostic code for the problem.

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.

This is a very known issue that has been reoccurring with GMC Acadia. The torque converter slipping. That cost alone is over $7.000 for the transmission. I am still making monthly payments for my 2021 Acadia. With rising cost above the board GMC could have resolved this issue before releasing this vehicle to the public for purchase. Only had this vehicle for 2 years and already a new transmission is needed. Other individuals i personally know have the same issue. From my research GMC is aware and fails to do a recall on this issue.

I am submitting this complaint regarding ongoing mechanical and electrical issues with my 2021 GMC ACADIA that have been occurring intermittently for approximately the past year and a half. The primary issues involve the coolant temperature sensor, thermostat system, engine cooling fan, and dashboard warning messages. The vehicle repeatedly experiences problems related to the coolant temperature sensor and thermostat. During these episodes, the engine cooling fan continues running even after the vehicle has been turned off, sometimes for an extended period of time. In addition, the dashboard frequently displays the warning message: “Steering Assist is Reduced – Drive With Care.” These warning messages and symptoms occur off and on without consistent resolution. The vehicle has already undergone repairs, including replacement of the radiator, yet the problems continue to return. Despite previous service attempts, the underlying issue has not been permanently corrected. The recurring nature of these problems raises concerns about the reliability, safety, and dependability of the vehicle, especially considering the steering assist warning and possible overheating or electrical system concerns connected to the cooling system malfunction. The repeated failures have caused significant inconvenience, concern for safe operation of the vehicle, loss of confidence in the vehicle’s reliability, and ongoing disruption due to repeated repair needs. I am requesting a thorough diagnosis and permanent repair of the coolant temperature sensor, thermostat, cooling fan system, and any related electrical or control module issues contributing to these recurring problems.

Bought the acadia in june of 2021, in december of 2022 had to have the radiator replaced due to it leaking. This was found on routine maintenance and was not having any issues whatsoever. I received no alerts on my dash such as a check engine light. Fast Forward to March 2026, I received a message of "steering assist reduced. drive with care." The engine seemed like it was still running despite the car being off. This was happening intermittently and definitely not every time I drove. I made an appointment for the regular oil change and to have this message investigated. Initially they told me it was the temperature regulator, however, they put a new regulator on and tried to re-pressurize the system. The system failed to re-pressurize due to the radiator leaking AGAIN. Of course, there was a 2 year warranty on the radiator after it was replaced initially and now we are about a 1.5 years outside the warranty.

The camera system has failed. The screen is black and there is an exclamation point and a camera on the screen.

Rear view camera won’t display when out in reverse. Also, when the camera does come on, it’ll flicker off and on

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.

The contact owns a 2021 GMC Acadia. The contact stated that while driving at an undisclosed speed, the check engine warning light illuminated. In addition, the coolant fan was running after the engine was turned off. The vehicle was taken to Auto Zone to be diagnosed due to the check engine warning light being illuminated. The contact was informed that DTC: P1098; was retrieved, which indicated a fault with the coolant control valve. The vehicle was taken to the dealer, where it was confirmed that the coolant control valve had failed. The vehicle remained at the dealer unrepaired. The contact related the failure to the Manufacturer Recall Number: N252508341. However, the VIN was not included in the recall. The manufacturer was made aware of the failure and advised that the VIN was not under recall. The failure mileage was approximately 69,000.

My vehicle’s steering became dangerously stiff while driving on the highway, nearly causing my wife to be involved in a serious accident. While she was traveling on I-95 in Miami, Florida, the steering suddenly got so hard that she could barely control the vehicle and was unable to turn the wheel properly. This created an extremely dangerous situation and put her life, as well as the lives of others on the road, at risk. She was thankfully able to get off the highway, and I had to come take over the vehicle to make sure she got home safely. This was terrifying and completely unacceptable. A failure like this should never happen while a vehicle is in motion. When I took the vehicle to the dealership, I was told I would have to pay over $3,500 for the repair. That is outrageous for such a serious safety issue. I also found information online showing recalls for similar steering problems in GMC Yukons, yet GMC Arcadias do not appear to be included. That is deeply concerning, especially since this same dangerous defect is clearly affecting my vehicle. This issue could have caused a major crash, severe injuries, or even death. GMC needs to take responsibility for this problem instead of forcing customers to pay thousands of dollars for a dangerous defect that should be addressed as a safety recall.

Car has had multiple issues with check engine light coming on for the last 2 years and stays on especially during the winter months. The purge pump has failed multiple times. The cooling fan has run after engine shutting off for multiple years now. The thermostat has been failing for the last 6 months. Now yesterday low power protection suddenly turned on driving on the expressway limiting power in the middle of traffic. Was able to get off at exit without accident and get car home. I guess we have to pay out of pocket to get fixed. This is a known issue that GM fails to include every VIN with the 2021 year or certain models and VINS.

The contact owns a 2021 GMC Acadia. The contact stated that while driving approximately 30 MPH, the vehicle started running rough before the vehicle stalled. The contact attempted to restart the vehicle, but the vehicle failed to restart. There was no warning illuminated. The vehicle was towed to a local dealer, where it was diagnosed and determined that the fuel pump module had failed and needed to be replaced. The dealer informed the contact that the part to do the repair was on backorder. The contact researched online and associated the failure with NHTSA Campaign Number: 20V639000 (Fuel System, Gasoline); however, the model year and VIN were not included in the recall. The manufacturer was informed of the failure and referred the contact to the NHTSA Hotline to report the failure. The failure mileage was approximately 46,000.

Car was taken in for an oil change at 62k Miles. Dealer advised that it needed a radiator replaced. At 64k miles it was brought into the dealer for warranty work due to a failing thermostat. While being diagnosed, we were told not only the radiator needed to be replaced, but the oil cooler also needed to be replaced. So a 5 year old car with just over 60k Miles had the thermostat/sensor fail and need to be replaced. A radiator fail and need to be replaced and and an oil cooler fail and need to be replaced. Vehicle has been at a GM dealer for all maintenance. No crashes or reasons these parts should fail. Vehicle has never towed anything to but any sort of strain on the cooling system.

Had vehicles looked at twice and serviced once for the transmission slipping. No issues were found when looked at and light was deleted. Took to another mechanic who drained and refilled transmission. Transmission still slips after service. This happens at acceleration and continues til 3rd gears where it jerks in between gears. Stops while driving continuously, the starts up again if stopped for any reason.

The contact owns a 2021 GMC Acadia. The contact stated while driving at an undisclosed speed, the check engine warning light illuminated and DTC: P04FB; was displayed. The vehicle was taken to the dealer where it was diagnosed with moisture of the crank case. The vehicle was repaired. The contact stated that the failure was a quick fix and was covered under the warranty. The contact stated that the failure had occurred several times and was covered under warranty. The contact was informed that there was no fix for the failure. The manufacturer was not made aware of the failure. The failure mileage was approximately 37,000.

Odometer Fraud. The contact purchased a 2021 GMC Acadia. The contact discovered a mileage discrepancy after the purchase. The vehicle was a dealer sale. At the time of purchase, the mileage was approximately 29,000. The contact attempted to trade in the vehicle, and the purchasing dealer checked the VIN and retrieved a Carfax Report. The Carfax Report indicated that the mileage on the Title on 11/04/2024 was 58,000; however, on 02/04/2025, the mileage was 28,000, and the vehicle had been in an accident in the past.

Been happening for a year and a half. Muffler is very loud and rattles constantly. Getting worse over time. There is a current recall but my vin isn’t included even though my car is having the same issue.