2018 GMC Acadia

The transmission was failing to shift and jerking me forward in the vehicle. The check engine light came on. I was on the highway going at high speeds. Also, my vehicles Internet connection dropped. I pulled off the highway and turned off my vehicle. While starting my vehicle again and attempting to go into reverse, it would not reverse and it would not drive forward . It would just rev the RPMs. My vehicle has been sitting at the dealer for two weeks. They have not looked at it yet. The police were not called as there was not an accident, thankfully. The warning light came on as the vehicle was failing.

Shift to park error notice comes up on dash when car it turned off and in park. Car is clearly in park, but error code “shift to park” appears on screen. Beeping occurs until car is turned off and shifted to R or D and then shifted back to park and turned off. This error happens several times a week, including twice today 6/22/24. I have to restart my vehicle and shift it to R or D then back to park SEVERAL times before the error is cleared.

The contact owns a 2018 GMC Acadia. The contact stated that while driving at an undisclosed speed, the vehicle briefly accelerated and decelerated erratically, after which the vehicle inadvertently lost motive power. The contact was able to pull to the shoulder of the roadway, where the vehicle was able to restart, but the failure persisted, and the vehicle was unable to accelerate above 20 MPH. The check engine warning light was illuminated. The vehicle was towed to an independent mechanic, who diagnosed a failure with the transmission. The contact was informed that the transmission needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 120,000.

GM has acknowledged that there is a "Shift to Park" problem with 2017 and 2018 GMC Acadia's. This design flaw/ part failure does not recognize that the vehicle is actually in "Park" so you cannot shut off the engine. In addition, the dash lights remain on which eventually drains the battery. Sometimes the car will roll as if it's in Neutral. GM is very aware of this problem. However, they do not have a permanent solution. GM should be required to issue a nationwide recall to correct the situation by totally disabling the electronic part. In six years of ownership, I've encountered this problem 3 times: 5-14-19, mileage 13,266, 1-27-21, mileage 29,381and most recently 5-30-24, mileage 65,057. This 3rd repair cost me $721.88.

SHIFT TO PARK - I originally thought I was turning the car off too quickly. I would put the car in park and hit the button. Then I would get an error message (with Loud beeping) "SHIFT TO PARK." The car will not turn off completely or stop beeping until i turn it back on, and shift into drive and back into park. This last week the problem has escalated and keeps giving me the error message. I have had to leave my car with loud beeping and unlocked. I am driving with a battery charger hoping I will not have to use it. I am shocked this is NOT a recall.

Seemingly at random a warning will pop up on the driver dashboard “Steering assist is reduced at this time”. This will lead to a engine coolant temp reading of 0 degrees, no a/c and reduced steering functionality. Through further investigation the OBD code P0128 tells us it’s a faulty Thermostat or Thermostat sensor. Even if you get these parts replaced, the issue still comes back. I’ve seen these exact complaints at least a thousand times across multiple years of this model/make 2016,2017,2018,2019. This is clearly a manufacturers fault and needs a recall before people get hurt.

The thermostat housing fails and is a known issue which causes the car to overheat and they said it will start of fire or shut down and loss of steering assist. The dealerships know about the issue and GMC does nothing leaving people with large repair bills or inoperable cars. the system won't let me upload my receipts here is the part #12678780 I was told by the dealership this is a known issue and they my emissions warranty only covers the thermostat but not the housing, but that they are 1 piece, playing games.....