What 97 owners told NHTSA about the 2020 GMC Acadia Limited

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.

NHTSA ODI 11704049

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.

NHTSA ODI 11702024

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!

NHTSA ODI 11701183

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.

NHTSA ODI 11701097

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 an accident to have something done about this.

NHTSA ODI 11700749

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.

NHTSA ODI 11698525

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 thermostat parts in stock because this failure is so common on Acadias. There were no warning lamps or symptoms before any of these failures occurred. All repairs and diagnostics—including the current issue—were done at the same GMC dealership where I’ve always had my vehicle serviced on time. I’ve been a loyal customer and maintain my vehicle according to the recommended schedule. Despite that, I have faced repeated high-cost repairs on a 5-year-old vehicle with relatively low mileage, which has been financially and emotionally overwhelming—especially as a parent who recently lost employment. Having the transmission, timing cover, and now thermostat all fail in such a short time clearly raises concerns about the reliability, safety, and manufacturing quality of the 2020 GMC Acadia’s powertrain and engine systems. Given that GM has already covered most of the transmission and timing cover repairs and dealerships acknowledge frequent thermostat failures, this appears to be a systemic defect that warrants formal investigation.

NHTSA ODI 11697288

Vehicle will shutter or buck at variable speeds like, 35-38 mph, 40-45 mph and so on. if I take my foot of the gas and reapply it will shutter buck again at almost any speed. I took it to a mechanic and there are no codes, no check engine light. Shop recommended changing the transmission fluid so we did. Car still responds the same way, shutters and bucks when reapplying fuel pedal or slow acceleration.

NHTSA ODI 11689632

The contact owns a 2020 GMC Acadia. The contact stated that while driving at various speeds, the vehicle stalled. There was no warning light illuminated. The contact stated that while his wife was driving at an undisclosed speed at an intersection, the failure recurred, and the vehicle stopped in the middle of the intersection. The vehicle failed to restart, and the driver was unable to pull over to the side of the road. The vehicle was towed to an unknown dealer, but was not diagnosed because the contact declined to pay the diagnostic test cost. The vehicle was then towed to the dealer where it was purchased, and the fuel pump module was replaced; however, the failure recurred 2-3 months later. The contact stated that the vehicle had failed to start. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 104,000.

NHTSA ODI 11688919

My 2020 GMC Acadia has experienced significant transmission issues, including [slipping / shuddering / “Service Transmission” warnings / loss of drive]. The problem has been diagnosed as a torque converter/transmission failure. GM has acknowledged known defects and issued recalls for 2019–2020 Acadia transmissions related to missing bolts in the start-stop accumulator endcap, which can cause fluid leaks and lead to torque converter/transmission failure. Many other owners have reported similar transmission issues, suggesting a systemic defect with the 9-speed transmission used in these vehicles. Despite these known issues, GM has declined to provide assistance with repairs. This failure compromises the safe operation of the vehicle, and I believe it warrants further investigation and potential recall.

NHTSA ODI 11687173

I'm not sure of the exact sequence of events here, but there are multiple exhaust leaks. One is a crack somewhere in the catalytic converter that is now leaking exhaust from the back of the engine into the passenger compartment. The other leak is at the point of a bracket which fastens the two front exhaust pipes together. At the time we first noticed an exhaust leak sound upon cold start, there were are around 58,000 miles on the car. Now a month later there are still less than 60,000 miles on the car. The dealership originally estimated repair costs to replace the catalytic converter and two front pipes at $3,200. When I had another service garage look at the problem, they asked why the GMC dealer wasn't willing to replace the catalytic converter under the 80,000 mile / 8 year warranty. When I raised this with the dealership, they said this was a "gray area" becasue they believe what happened was that the exhaust bracket at the front pipes failed first, which then caused the catalytic converter to crack. Ultimately, they indicated they would be willing to pay parts and labor related to the catalytic converter (approx $2,000) if we paid the other $1,200 to cover the front pipes. What I don't understand is why, when both Chevrolet and Buick have extended their front pipe warranties on comparable model years of the Chevy Traverse and Buick Enclave, which use the exact same part numbers for the catalytic converters and pipes to 150,000 miles/15 years, why GMC has not offered the same special coverage on the Acadia. Regardless of which cracked first, the front pipe bracket or the catalytic converter, there is likely an engine vibration/movement issue that casues the cracks, giving rise to exhaust venting into the passenger compartment. Since we have yet to be able to schedule the repair (catalytic converter was on back order), we can now only drive the vehicle with the windows down to lessen the exhaust smell. The Acadia deserves a Special Coverage Advisory on this.

NHTSA ODI 11685679

Car keeps throwing Poo14 code for VVt sensor, I’ve replaced the sensors and checked wiring on the side of the road and no damage found, went online and read multiple complaints and recalls on the same issue I’m having with my car. I enter my vin and no recalls have been found. I have a 2020 gmc Acadia Denali 3.6l v6. As well and the rear view camera cutting in and out multiple times anlmost causing an wreck. and a system update didn’t fix the issue.

NHTSA ODI 11679487

Valve body car would not go in park

NHTSA ODI 11677981

An error pops on the dash that says steering assist is reduced-drive with care, and the thermostat gauge does not work, nor does the air conditioner and the vehicle fan under the hood is extremely loud. This has been happening intermittently since September 2024. Basic research on the Internet is showing many people have the same issue with these vehicles. Further research suggests possible vehicle computer system issues. I don't know why there isn't a recall already.

NHTSA ODI 11659505

Heater Core broken

NHTSA ODI 11658163

While i was driving a code came on my dashboard that read "Steering assist is reduced drive with care". Soon after my check engine light came on. I pulled over not knowing what was happening. I took it to the garage to have it looked at and the mechanic stated that there are over 1000 gmc customers with this same issue and that the thermostat is stuck open. Which may cause major malfunction or even blow the engine. I looked up recalls for my vehicle and there are none but gmc issued a recall on other vehicles for this same issue. How do I get help here?

NHTSA ODI 11658259

Power steering system fails intermittently. Power steering goes and comes back on without warning, causing the driver to oversteer the vehicle. Mechanic performed software update, which did not fix the problem and told me the power steering module needs to be replaced, which would be over $1,000 for the part, plus labor and re-alignment. Additionally, the replacement power steering module is not currently available - it is on backorder.

NHTSA ODI 11655015

The vehicle stalls when air start kicks on so when stopped auto stop kick on and when your ready to go the go stalls to turn back on. I have also lost power to the car randomly. Power train issue on car keeps coming on with engine light. I have taken to dealer when car was under warranty and they were very dismissive to my issue. They changed some sensor under warranty And they said the issue was fixed. But the issue remains and it’s causing several issues to the car with Also a fueling code to the engine light

NHTSA ODI 11650043

Unknown

NHTSA ODI 11647126

When it rains(or car wash) my power locks don't work. I get locked out of my car. My car reset itself in the middle of an intersection(like I turned it off and back on again). One of my gauges is always not working. The sunroof doesn't work right. Water is getting in the electrical area somehow. I've taken it to two chevrolet dealerships, but no help.

NHTSA ODI 11646575

Transmission Control Value issues. I was driving my car and RPM spiked up high and I coasted and there was no acceleration the rear wheel tires locked up and I felt a jerk. Placed the vehicle in park and pulled hand gear shifter into Drive and the vehicle shifted back into park by itself. Same thing happened on placing the vehicle in reverse. Like the car had a mindset of its own. Luckily I was only going 20 miles per hour this could have been a fatality. This vehicle is not on the recall list. It should be because they use all the same parts.

NHTSA ODI 11636824

While trying to reinstall the evenflo car seat, the latch to lock the car seat into place failed. The metal on the car seat is broken. The car seat has been used in the vehicle for less than a year, and if I had not noticed this upon trying to move the car seat it could have caused a serious injury should my child have been involved in an accident.

NHTSA ODI 11635749

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.

NHTSA ODI 11629160

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.

NHTSA ODI 11627362

Once again (for the second time in a few months) the vehicle put me and my passenger in an extremely dangerous situation. We were driving down a 55mph country highway catching speed, somewhere around 45-50 mph and the car jerked so violently that it shook us even though we had our seat belts on. It then made a weird noise and felt like it was powering down so I stepped on the accelerator to try to bring it back up to speed and it sped up a little bit, jerked again (not as violently) and turned off. Luckily, since it was a country hwy and no cars were coming, I was able to coast into a driveway. I attempted to restart the car to turn around and go home but as soon as i put it in gear, it would shut off. I tried a few times and it would make a "tick tick, tick" sound but not start. I waited a few minutes and tried again and was able to get it to start, go in reverse and get back home. Once I got home it would not start again. Mechanic says it is the same issue and before, which was also part of a recall for this vehicle having to do with the fuel pump relay. I will be trying to tow this vehicle to the dealership for repair.

NHTSA ODI 11615054