2020 GMC Acadia owner complaints

Brand new vehicle. Purchased on 10/30/2020. Front collision keeps flashing a red light in the top of dash that shows up in windshield. This happens with no other vehicles on the road at random times. When the vehicle needs to stop or warn you it will not. It will just let you hit a pedestrian or another car. We noticed that the same thing is happening with the rear safety cross traffic.

Two days after purchasing a new 2020 GMC acadia I get an error on the display "sd card removed" along with various other error messages. Dealer talks to GMC tech line and they advise to replace radio. Radio was replaced and errors began same day I picked it up. Dealer is replacing radio again, but unsure if this will fix the issue. The vehicle does not work as intended as when you press the nav button various error messages pop up and navigation does not work.

The electrical, engine, and A/C systems failed. First our A/C stopped blowing cold. A warning light came up and said that driver assist was not working properly, and temperature gauge went all the way down to cold and did not move after that. It appears 3 things were malfunctioning. I was afraid to drive it for fear of burning up the engine due to an engine cooling malfunction and the car overheating. The A/C stopped blowing cold air but was still blowing warm air. The steering system alert was on the dash but wasn't an issue. I called OnStar to diagnose the problem and they initially said they didn't see a problem but based on what I described it would be best to have it towed. I later got an email that an issue was detected, code P0128. I called my dealership and they also said to have i

The vehicle’s lock/unlock feature is inoperable either via the buttons on the door inside the vehicle or via the key fob. There is no manual way to lock/unlock the vehicle from inside the vehicle. Driver and passengers could only exit vehicle via rear lift gate or thru the vehicle windows. Should driver or passengers have had mobility issues or not been able to crawl through the vehicle to exit via the tailgate, they would not have been able to exit the vehicle in the event of any emergency. Incident has happened on at least 3 separate occasions.

I noticed for months it was downshifting hard but transmission department was backed up I scheduled in September for an appointment October 26 and that morning I received a call to reschedule because they were still behind and had another appointment for November 10th. The morning of the incident 1st it did not want to start it would only turn over. When it started the check engine light was on (I called service he asked if I could drive it and told me to bring it in). Within 10 miles of driving, the car started to slow down. When I pressed the gas the RPMs would go up but the car would not accelerate. I was on the interstate so I started to coast to the side. When I got to the other side of the rumble tracks the fuel gauge warning came on saying no fuel (even though I had half a tank whic

Code P0128. While driving the vehicle gives a "steering assist reduced drive with care" the engine coolant temperature gage goes to 0 and the cooling fan runs until you turn off the car, and the a/c stops working. After replacing the engine coolant temperature sensor and harness the vehicle still does it. There are hundreds of reports of this happening online in forums. This is a safety issue when the vehicle is being driven.

front and rear camera not working blind spot indicator not working side mirrors warning of oncoming vehicles not working radio not working

I started receiving an error message that driver assist is reduced drive with car at 50k miles (i have an onstar diagnostic report and phone call made that day). It shut my car down and activated the parking break. I called Onstar at that moment it happened and they found nothing wrong with the car. It continued to happened several times after and each time I took it to the dealer they were unable to diagnose the problem. One time I was told there was a bulletin on it from GM, but not for the year of my car so they were not able to make the repair. When it finally started giving me the error all the time, they finally found it was the thermostat - $1600 and GM would not cover the part under warranty because I now had over the warranty miles even though it happened and was reported pri

The contact owns a 2020 GMC Acadia. The contact stated while stopped at a traffic light and depressing the accelerator pedal after the light had changed, the vehicle hesitated and then lurched forward. The contact stated that an unknown warning light was illuminated. The contact stated that while driving at an undisclosed speed, the vehicle was vibrating abnormally. The vehicle was taken to an independent mechanic to be diagnosed and it was determined that the transmission needed to be replaced. The vehicle was not repaired. The manufacturer was informed of the failure. The contact researched online but found no recall related to the failure. The failure mileage was approximately 80,000.

2020 GMC acadia. Consumer writes in regards to loss of power at low speeds and jerking with brake light illuminated. *ld *js

I own a 2020 GMC Acadia that has experienced multiple major mechanical failures within one year. In January 2025, at around 74,000 miles, the transmission failed completely with no warning or clear indication of what was wrong. The vehicle suddenly lost power while driving, creating a safety risk for me and my child. I was quoted around $12,000 for the transmission replacement initially before getting GM involved. GM covered all but approximately $3,600 out of pocket for me and also covered 100% of the timing cover replacement, which was found to be defective during the same repair. Now, at about 84,000 miles, the thermostat has failed, triggering the check engine light. This repair has not yet been completed and is estimated at around $1,500. My dealership informed me they keep thermosta

SIDE BLIND ZONE SYSTEM TEMPORARIALLY UNAVAILABLE message displayed in DIC, and system does not function. I can not rely on the system as it very often does this. This issue started on 12/08/2022. I feel that I am at risk of a crash as I rely on this system for blind spot detection. There are MANY forums that state that MANY other 2020 GMC Acadia's have this issue. I feel like this is a GM issue, and the consumer should not be left with the cost of any repair, if necessary. This is a safety risk and could result in death from a crash due to a failure of a safety system.

My front camera that detects the front collision and helps with adaptive cruise control just went dark. I thought maybe it would reset after turning engine off and restarting it, but it didn’t help. Not sure what happened.

The Automatic braking assist feature goes off at times when there is no threat of hitting something. It happens when pulling into a garage and also on the road while driving. There have been several occasions when this happened and the car suddenly brakes which could have resulted in being rear-ended. The car suddenly brakes even if there is no danger of running into a car (or garage) in front of me. It has not been inspected (yet) but it seems to be increasingly becoming more of an issue lately. There were no warning lamps or messages just the sudden, hard-braking and loud noise/buzzing it makes when it happens. There have been several occasions but I'm listing the most recent one below.

1. Shift to Park failure, P0700/P187e internal sensor, causing me to have to get a rebuilt transmission. 10/2025 2. Transmission shudder/hard-shifting ongoing 2022-2025 3. Coolant/thermostat issues. Steering Assist Reduced" message, fans stay on HIGH, no AC, engine temp on ZERO ongoing since 2024 3. Start/Stop button failure multiple times (replaced 3 times) 4. Rack and pinion/steering gear (would not return/ got stuck while turning) got new rack and pinion 2023 5. Water pump leaking, replaced 4/2024 6. Since 2023, have had ongoing “Timing OVER ADVANCED”, warning issues since 2023. This is TOO MUCH for a New car!!! I’ve owned MANY cars and NEVER had this many issues!!! There appears to be multiple design flaws with this model and similar models!

Steering Assist reduced drive with care message. This is an extremely common issue and should be a recall. ALOT of people including my dealer service advisor has this issue with their vehicle this message comes up fans kick on high a/c stops working and temp gauge stops working. It can be reset by unplugging battery or clearing the code.

The "Steering Assist is Reduced" warning came on the same time the engine thermostat display stopped working. Then the check engine light came on the same time the AC stopped working. At first I thought maybe it was just the battery, so I had that changed out. But the "Steering Assist" warning continued and the engine thermostat display was still stuck on "Cold" no matter what (note: the oil temp display still worked fine). Looking in to the problem, apparently a defective Engine Thermostat is a pretty common issue with this vehicle. Why isn't there already a recall on this? The risk of engine overheating is HUGE and dangerous. I called GMC and they want to charge and arm and a leg to fix it (the car has 47000 miles so is just out of warranty). I don't want to wait until there is

Engine coolant thermostat failed under 55,000 miles and had to have it repaired on my 2020 Acadia. The 2021 Acadia has a recall on the thermostat.

The contact owns a 2020 GMC Acadia. While the vehicle was at the dealer for maintenance, the contact was informed that the radiator was leaking and needed to be replaced. In addition, the contact was advised that there was coolant intrusion. The contact stated that it was not specified if the coolant intrusion had gone into the engine. No warning lights were illuminated. The vehicle was not repaired due to the cost. The contact was informed that the fueling system needed cleaning service, as well as the brake fluid and transmission fluid needed to be serviced. The vehicle was taken to several independent mechanics, and no leaks were found with the radiator. The manufacturer was not made aware of the failure. The failure mileage was approximately 62,000. The VIN was not available.

Recently purchased a 2020 acadia denali. When parking at any incline the parking brake automatically turns on. Dealer is not sure why, but no where in the manual does it state this is normal. To disengage brake vehicle has to be put in gear with foot on brake to turn off. The parking brake should turn off when vehicle is in park with foot on brake but it does not. Dealer is unsure of issue and has an open case with GMC to investigate.