What 389 owners told NHTSA about the 2018 GMC Acadia Denali

The contact owns a 2018 GMC Acadia. The contact stated that after parking and then attempting to turn off the vehicle, the message " Shift to Park" was displayed. The contact stated that the vehicle was able to be parked and turned off successfully after various attempts, which included restarting the vehicle and engaging the parking brake. The vehicle was not diagnosed or repaired by an independent mechanic or a dealer. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 80,000.

NHTSA ODI 11751749

When trying to put car in park a "shift to park" notice appears on dashboard not allowing the car to be turned off. It takes multiple attemps be able to get the car into park and turn OFF. This has been an ongoing problem for several years and reported to the dealer. To date the dealer tells me there is nothing wrong with the car. Battery has been changed multiple times.

NHTSA ODI 11749867

While driving the temperature gauge drops from normal to cold , the dash displays " steering assist reduced" and the fan is very loud . My mechanic said the thermostat and or sensor needs to be replaced . When he resets with the reader its good for about a week and temperature gauge is normal. After seven days it repeats I only have 40,000 miles on the vehicle and its a 1,400 dollar job. I believe this should be a recall because i have seen a lot of the same complaints in this forum and what about the people who have the same problem but don't complain ?

NHTSA ODI 11749432

When I’m driving on the highway, I get a message on my dashboard saying steering assist reduced, drive with care. I have taken to the GMC dealership and they will not cover this repair even though it would be covered for 2021 GMC. When this happens, my car makes a loud noise and my steering wheel does not feel right. I do not feel safe.

NHTSA ODI 11748910

Gear shifter is not registering that the vehicle is in park. Because of this issue I have to sit in the vehicle for up to 15 mins trying to get it to register that it is in fact in park and can turn off. If I didn't take the time to do this, it would kill my battery. Unfortunately with the heat index, the vehicle gets hot very quickly and im now worried about getting hot stroke trying to get it to register it is park. This is a known issue with the vehicle that has an active recall for other vin numbers with the same issue.

NHTSA ODI 11748238

Hesitants and Shudders when shifting into 2nd gear.

NHTSA ODI 11748054

this is the second time I am having to replace gear shift with under 160000 miles. Turn the car off and it tells me the car is not in park when it is. It can not tell what gear it is in or when. AGAIN. This is the second repair

NHTSA ODI 11743789

Shift to park Malfunction again, 4 th time!! 1000$ to fix is ridiculous

NHTSA ODI 11742706

The contact owns a 2018 GMC Acadia. The contact stated while driving at undisclosed speed, the steering assist reduced warning light illuminated. The contact's husband attached a portable diagnostic tester to the vehicle, and P0128 was the failure code. The contact referenced an unknown recall; however, the VIN was not associated with a recall related to the failure. The manufacturer was made aware of the failure but provided no assistance. The contact was advised to contact the NHTSA Hotline and report the failure. The failure mileage was approximately 78,000.

NHTSA ODI 11741369

When I put the shifter to park, it still dings and tells me "shift to park" and I struggle to make it go away and to be able to make it stop and be able to lock the car. It happens every time I drive it. Thank you

NHTSA ODI 11739333

Shift to park error Vehicle won’t shut off

NHTSA ODI 11739392

I am getting the known P0128 code. My engine says it's cold when it's not, my AC isn't working, and I am getting a message that says "Steer assist reduced. Drive with care". This is a known problem and complaint of the GMC Acadia.

NHTSA ODI 11738997

the transmission kept slipping. the car continued to lose power until it just wouldn't go anymore. The mechanic said it is definitely the transmission and drive shaft but my particular VIN is not included. I am looking at $7,000 in repairs on a car I owe $13,000.00

NHTSA ODI 11738766

For the last 6 months, I keep getting a "shift to Park" message on my dashboard indicating that my vehicle is not in park (in which it is). The problem is getting wors, so I called GMC on 5/14/26 to inquire and was informed that my VIN number WAS not include in the resent class action lawsuit for this issue. I then found out by searching myself on line for other complaints that GMC is very aware of this situation and yet refuses to fix the issue free of charge to customers. According to TSB 19-NA-206, t does list my year , make and model of vehicle affected by this faulty part. On 5.15.26, I called the dealership to inquire and was informed that my VIN was not covered under warranty (which I had already known), and that that service I would have to pay lots of money out of pocket for it. The service tech did look in the system and claims (without me even knowing that they had did that repair already....He lied I'm for sure). I informed him well if they did repair that part, and I'm still getting an error message about the same thing, clearly its faulty and the dealership should be responsible for fixing it. This was not the case as I was informed it would have to be out of my pocket. This mess is unfair! GMC is well aware of this faulty pat on vehicles, and to refuse to fix it free of charge is just down right hurtful! GMS is responsible for repairing this part on everyone's vehicle as it is a hazard to everyone and the community to have a vehicle unstable to be able to slide away from a parked position. This is such a road hazard, something has to be done about it. It's not far that I am expected to pay for these faulty wiring costs out my pocket when its a faulty issue GMC is very well aware of.

NHTSA ODI 11738057

I have a 2018 GMC Acadia SLT with the thermometer and temperature sensor that throws the steering assist error message, engine fan turns on and AC shuts off.

NHTSA ODI 11735300

When I put the car in park and shut off the vehicle, I am getting a shift to park message with an audible sound. The car is in park already. Happens every time almost. It’s not showing up as a recall under my vin. Just got the car. I have seen more recall issues on Google and am concerned those will also occur which are more serious and aren’t listed either.

NHTSA ODI 11734468

The contact owns a 2018 GMC Acadia. The contact stated that while the vehicle was parked and turned off, the “Shift-to-Park” warning light illuminated with a continuous audible alert. The vehicle was unable to recognize that the transmission was in park(P). Several attempts were needed to shift to park. The battery was disconnected to turn off the audible alert. The contact stated that the vehicle was previously repaired under an associated recall. During the recall repair, the shifter and wiring harness were replaced with Part Numbers: GM84955381 and GM84733196. The manufacturer was not notified of the failure. The failure mileage was unavailable.

NHTSA ODI 11734045

2018 Acadia Denali with less than 50,000 miles on the vehicle. Had to replace the coolant temperature sensor and thermostat. Less than 30 days later. The check engine light came on and the code was coolant temperature sensor and thermostat. Code P0128$07E8

NHTSA ODI 11733007

thermostat and temp sensor issue

NHTSA ODI 11732763

The contact owns a 2018 GMC Acadia. The contact stated that upon parking the vehicle and attempting to turn off the vehicle, the message "Shift to Park" was displayed while the gear shifter was in park(P). The contact parked the vehicle and turned off the vehicle after several attempts. The contact related the failure to an unknown recall; however, the VIN was not under recall. The dealer and the manufacturer were not contacted. The vehicle was not diagnosed or repaired. The failure mileage was approximately 149,000.

NHTSA ODI 11730784

Vehicle warning light, and noise alerts when placing in park. Vehicle does not register PARKED. Vehicle has to be restarted several times and shifter moved in and out of park until registers as parked. When viewed by mechanic, it was stated there has been a recall to contact manufacturer about recall, but none noted on site.

NHTSA ODI 11728145

Vehicle dies with no warning, no warning lights, no power even emergency flashers are inoperative, almost like it got hit by an EMP

NHTSA ODI 11725361

My car says Shift to park when I try to turn it off. Leaving my battery to drain.

NHTSA ODI 11725071

Gear shift fails to register that it’s in fact in park position on gear shift but dash message reports “shift to park”, and warning beeping sound won’t stop and doors won’t lock. After restarting and reshifting the gears and / or pressing gear shift button up to 20 times or more until the dinging noise stops and only then can the car be locked. Everyday since 4/20/2025

NHTSA ODI 11724190

Car does not turn off, says “Shift to Park” but car already is in park and car won’t turn off.

NHTSA ODI 11723747