2020 GMC Acadia

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 it towed so they could check it. We were not in a position to have the car towed and for it to sit in the service department for 5 days (that was what their queue backup was like then). I took the car to a nearby shop to have it checked. Because I was afraid to drive it we I got it there by disconnecting the battery. A/C was blowing cold like Arctic air and the temperature gauge went back to normal. We got it to the shop (a few miles away) and they could not duplicate the issue due to the battery disconnection "fix". They said the car would be temporarily functioning per usual but the problem will come back again soon and to bring it back when it happens. It happened 2 weeks later (2 hours from home/stuck in traffic). We found an auto parts store and bought a wrench to disconnect the battery again to get home and all was good once we did that "fix" again. We have a service appointment to have it repaired. Two quotes I got were for $1600 and $2200. Temperature sensors/thermostats were suspected to be the cause of the issue. The auto shop stated they frequently see this issue (P0128) with GMC vehicles in recent years, even when they are only a few years old. Ours is 4 years.

The car has parking brake on unable to disable.Have to put in drive force the system to move. Same with reversing the car. Air bags not working. Seat belt restraint on when we are wearing them. Left turn signal failure. Steering limited caution sign on. ESC sign on. Engine light on. Transmission unable to shift soon light on. Traction lights on. ABS brake light on. Temp says -40 degree when 30 out. I’m finding this unsafe to drive. Call GMC that told me to start On Star diagnostic. Pull up at least 4 codes And today the transmission indicators came on. Not sure what to do. The car has low miles. But I have stopped driving as of today due to break down or serious malfunction while driving.

The contact owns a 2020 GMC Acadia. The contact stated that while driving at various speeds, the vehicle was shuddering. No warning lights were illuminated. The vehicle was taken to a local dealer, where it was diagnosed that the torque converter needed to be replaced. The vehicle was repaired; however, the failure persisted. The contact stated that while starting the vehicle, and while driving at various speeds, a buzzing noise was heard coming from the engine compartment. The contact also stated that while driving at an undisclosed speed, the vehicle stalled with the anti-theft system warning light was illuminated and the vehicle lost motive power. The vehicle was able to be restarted; however, the contact stated that unknown alarm chimes were heard. Additionally, the liftgate opened independently and various other unknown warning lights illuminated, and messages were displayed. The contact stated that the vehicle lost motive power and failed to restart. The vehicle was towed back to the dealer however, the cause of the failure could not be duplicated. The vehicle was not repaired and remained at the dealer. The contact was made aware that the warranty had expired. The manufacturer was not made aware of the failure. The approximate failure mileage was 2,000.

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 which was verified through the service department) and the car came to an abrupt stop. Had I not gotten over when I did the car would have stopped on the highway. I tried to turn it on to move it farther off the road and it would not. It started to just turned over like it did when I originally tried that morning (all over the occurrences happened while I was on the phone with Adrienne who i contacted through the gm help line).