2020 GMC Acadia Complaint Log

While idling, my vehicle has a strong exhaust smell inside the cabin. Per the GM Dealer, this is due to faulty flex hose.

On multiple occasions the car will suddenly brake or like throw on the parking brake and stop suddenly no warning

I bought the car at the end of October 2025, so it was always cold till last month. Last month the first day it’s warm I get a warning saying my steering assist has been limited with a code saying the thermostat needs replacing as well as the sensor. This is a known issue with these vehicles and now I have to pay $1500 out of pocket to have fixed because my limited warranty expired 2 weeks before it was warm enough to trip the codes. This is ridiculous especially seeing as I am disabled and can’t afford an extra $1500 after spending $7000 for the down payment!

The contact owns a 2020 GMC Acadia. The contact stated that the doors failed to open from outside the vehicle while using the key fob or while attempting to open the doors manually. The contact entered the vehicle from the rear hatch door and discovered that the door lock and unlock buttons were inoperable. The contact pulled the door handle to manually open the door from the inside. The cause of the failure was not yet determined. The manufacturer and local dealer were notified of the failure, but no assistance was provided. The failure mileage was 68,140.

The contact owns a 2020 GMC Acadia. The contact stated that the AC was inoperable. The message “Driving Assist Reduced - Drive with Care” was displayed. The vehicle was taken to the local dealer, where it was diagnosed, and determined that the battery needed to be replaced. The vehicle was not repaired. The vehicle was taken to an independent mechanic who replaced the battery. While driving, the message "Driving Assist Reduced" was displayed. The contact was concerned about driving the vehicle due to the failure of the steering wheel. The contact stated that the failure was related to GM Special Coverage: N252508350. There were four attempts to contact the manufacturer, but there was no response. The failure mileage was approximately 47,000.

Check engine light codes: P01F0; P0128 Engine coolant thermostat opening at a lower temperature than intended. Replace thermostat.

My 2020 GMC Acadia slt has a a warning message that pops up on the dash display which reads power steering operating at reduced assistance. Please proceed with extreme caution. At high speeds the wheel kinda pulls and is loose for handling. It also atfff conley buick out by the conley buick sericexx2020 acadias. I don't not54⁴ lower rates of speed becomes extremely hard to maneuver . Almost zero ability to turn the steering wheel. I'm disabled and really can't afford the costly repair. It seems to be a very dangerous problem and well known to compromise ones ability to control the 2020 Acadia danalis. I had my suv ckd out at conley buick the results were power steering module needs to be replaced. When driving down the road the steering becomes dangerously loose especially

My infotainment screen just has lines on it. I am the second owner of this vehicle. It just stopped working on day and has not come back. I cannot use my back up camera system now either. I have read where this has been an issue with the 2020 model and a possible crimping in the wiring system. I am wondering if this is the issue here. The car has been in no accidents under my ownership.

Reduced steering assist came up on screen then as we went a few more miles the tire pressure on right front dropping like crazy for no reason on screen in vehicle stopped looked at tire no issues.

Rear heater line leak detected during evaluation of engine code P01F0 and empty expansion tank was noted. There was never any puddle in my garage prior to the incident, and nothing detected after the fact either. Pictures included demonstrate a leak at the double-crimp near the farthest rear point of the vehicle. The other hose behind the drip photo was also leaking at the crimp under the secondary piece of hose insulation. The design of the system requires replacement of the entire heater line assembly (4 pipes, associated hoses and fittings) traversing the entire length of the vehicle. I was told this is a dealer-only part.

Failed component was thermostat and I do not have possession of it. Over several months, I would receive infrequent and unrepeatable messages of "steering assist reduced" and my temp gauge would drop all the way to the cold side. No other recorded codes were being set after frequent trips to Autozone for verification and there were no check engine light warnings. No other signs of vehicle malfunctioning were present either. Recently, a code was finally set P01F0, so I had something tangible to take into shop as the prior condition was not repeatable. Hoping it was only the coolant temperature sensor, then ultimately learned the thermostat had failed - the much more expensive repair option. Seeing this complaint relatively frequently with the 3.6L engine on NHTSA. Plus, the tech says he has changed at least 100 of these - Acadias, Traverses, Enclaves, etc., any GM product with this engine and poor design/position for the thermostat.

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 "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.

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.

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!

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.

Thermostat

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.

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.

Valve body car would not go in park

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. 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.

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.

The torque converter in the transmission has been vibrating for over a year now. I can imagine it is causing more damage to the rest of the transmission. Now I can feel the shifting starting to get rough, loss of power, and dark transmission fluid. I had the problem confirmed with an independent service center. There have been no warning lamps as of yet. But it's only a matter of time that I will need a torque converter replacement and/or full transmission replacement.

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?

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.

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

Unknown

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.

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.

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.

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.

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.

Heater Core broken

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.

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.

After heavy rain or a carwash, the door locks and lift gate don't work from key fob. And the vehicle says no remote detected and has trouble starting. After a day or two they start working again. It caused U0422 (invalid data received from body control module). On forums it says it can be water leaking into the vehicle and shorting out the BMC from either the HVAC drain or a weatherstrip somewhere. Now my rear passenger door locks don't work at all. Dealer wants to replace the actuators but can't find the root cause of the problem. Issue has been going on for over a year now.

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.

Transmission gave out

Rear-View Camera Failure: The rear view camera functions intermittently. While in Reverse, the screen goes black, with a red triangle and a circle with a line through it. This SAFETY ISSUE increases risk of incidents resulting in injury and/or property damage while the vehicle is in reverse. I understand there already exists a NHTSA RECALL (NHTSA Campaign Number: 22V709000) however, it states that only vehicles equipped with the optional Surround Vision feature are affected. My vehicle does not have the 360 Surround Vision (RPO UV2). but is experiencing the same SAFETY ISSUE!

The car would not start. It would power on but would not turn over. We had it checked out by a mechanic who tested it and found that the fuel pump module was not operable. When he went to replace it, he found that the one he was removing was aftermarket so this issue had happened before, apparently, before we bought it. We bought it with only 24k miles so it needing to be replaced that early is concerning. And now at around 50k it had to be replaced again. Researching this issue, I have found many folks reporting similar situations. This needs to be investigated.

The contact owns a 2020 GMC Acadia. The contact stated while driving from a complete stop and depressing the accelerator pedal, the vehicle hesitated to respond. The contact stated that the failure also occurred while driving at various speeds. Additionally, the contact stated that the vehicle experienced unintended downshifts while driving. The contact stated that the engine revved significantly without the accelerator pedal being depressed. The messages "Unable to Shift Gears" and "Service Vehicle” were displayed. The contact stated that the failure had been recurring while driving. The dealer was notified of the failure and an appointment was scheduled for diagnostic testing. The vehicle was not yet diagnosed or repaired. The contact related the failure to NHTSA Campaign Number: 20V668000 (Power Train); however, the VIN was not included. The manufacturer was not notified of the failure. The failure mileage was approximately 80,000.

Backup camera continues to intermittently fail even after recall remedy was performed. When placing the car in reverse, the backup screen goes black with a warning symbol on the screen that the camera is not working. This has happened intermittently for the last couple years. I've taken it to a GMC service center 5 times for this issue (3 of these visits were after the recall remedy was performed). The service has fixed the issue but it only lasts for a short time before reoccurring.

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.

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

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.

The contact owns a 2020 GMC Acadia. The contact received notification of NHTSA Campaign Number: 22V709000 (Back Over Prevention) however, the part to do the recall repair was not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The dealer was made aware of the issue and confirmed that parts were not yet available. The manufacturer was made aware of the issue and confirmed that parts were not yet available. The contact had not experienced a failure. The VIN was not available.

My steering assist is reduced drive with care message is on. The AC is no longer working and the fan is constantly running and sounds horrible. The temperature gauge has not come off of cold. After researching this issue online-it looks like this is a constant problem with Acadias from 2017-current. People are talking about the cost being between $1100-2400 to fix. There is a service bulletin out about this issue(17-NA-158) May 2017 If GMC knows that this is a problem why are they not recalling them?? My car was purchased brand new and of course is out of warranty like most others(the extended warranty doesn’t cover it either) GMC needs to recall these vehicles and fix this issue!!!!!

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.

I bought my car [XXX] it had 7 miles. I loved my car. Then in January 2021 things just went crazy. It started with park light on. My forward brake assist warning didn’t work, my back up camera in and out . My braking and stability were on and off. Then weird codes like. Engine at half power, unable to shift soon and speed control out. Then if I hit a bump message went away and speed control back on. I’ve taken care into another GMC dealer because dealer I bought my car at , closed up and took off!! Took it to closet dealer. Not long after repairs same issues started! So many different problems all at once! I have been treated horribly during these issues by dealership and extended warranty company. Dealer had my car for 3 weeks ! They couldn’t figure out the problem. I sat there for 4 hrs sent me home told to come back for 9 mile test! Why in 4 hrs that wasn’t done. So again the unable to shift message back on! I get in my car it starts but won’t shift ! Dealer charged me 250 to tow to shop! When they said I’d be fine ! I had more issues again and again! I’ve been driving over 40 yrs no accidents. I bumped into someone during a huge traffic jam in Ohio! Braking didn’t work no warning even . I should speak to a lawyer and could explain more to a person on filing these complaints. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)