2019 GMC ACADIA Engine Problems

Check Engine Light came on with message of "Steering Assist is Reduced Drive with Care". This same thing happened to my sister-in-laws 2019 Acadia 2 months earlier. Took it in right away to the dealership to find out it's the thermostat, it's a common/known issue and it isn't covered under my extended warranty and will cost ~$1300. I'm seeing this is a common issue for Acadia's and has not had a recall, don't understand why. It's one thing if this is a easy part to replace, but GM has made it so that most people now need a dealership or auto repair shop to fix it.

I'm going to have to replace my thermostat and most likely my sensor. It will pop up saying (steering assist is reduced drive with care) my temperature gage on my dash will sometimes will not go up, my heat is acting funny. I've had also when I put it in park saying it's not actually shifted into park.

I bought a car about 2 months ago and they did not tell me the thermostat was bad and they won’t cover it.

Thermostat is repeatedly going bad. Throws Steering Assist reduced. Had it replaced twice and it’s bad again.

Car stalls and transmission dies

Due to negligence of gmc wright of wexford during the replacement of 3rd new transmission they did not clamp a hose together causing coolant to leak and my thermostat to come on n off. Causing further damage to my vehicle

Unknown My 2019 Acadia Denali has/is been repaired 6 times in 1 1/2 years for engine oil leaks , has had transmission repairs twice , radiator repair and replacement. Also suspension warranty work as well . I feel the oil leaks is and has been excessive and dangerous due to no warning lights never displayed to alert me to check oil

Last week, the coolant gauge , on our 2019 GMC Acadia, was reading below "C".... The "Steering Assist" warning was disabled on the on-screen display and the Air conditioning stopped working. Took the car to a mechanic, who read the codes.... Mechanic stated that all symptoms were based on a defective GM thermostat. The thermostat was "stuck-open" causing the "steering assist" to be disabled as well as the A/C from being disabled as well. It seems GM has updated the part since when the series of Acadia were manufactured. After getting it repaired, at of our pockets, we researched and noticed that thousands of other GM Acadia owners had the same exact 3 symptoms: (1) malfunctioning coolant reading (2) "Steering assist" disabled (3) a defective ("stuck-open") thermostat..... Symptoms were exactly the same for all parties involved. We have owned many vehicles never had a thermostat fail before 65k Miles.... It became a safety issue since the car disables the "steering assist" based on the thermostat being stuck open. Contacted GM corporate which stated unless a recall, there would be no compensation. GM needs to make it right for the thousands of GM owners whose car has the 3.6L engine In short, this is a major issue since the car's steering system is NOT working correctly We would like a recall to be initiated. Thank you.

Shift to Park Vehicle does not recognize the gear shifter is in the park position. Vehicle does not fully shut down.

My coolant thermostat went out, causing my AC and steering assist to stop working. I have spoke to multiple other people who have had this same issue with their GMC Acadia and I believe this should be a recall. It’s going to cost me $1200 to have this issue resolved.

Component: Shifter Assembly & jumper harness Safety concern: Can't turn off vehicle - Carbon Monoxide poisoning, physical safety when parking not at home, as I would have to leave vehicle running... Message in dash was present when I brought vehicle to dealer. Dealer also replicated No inspection other than dealer. Part returned to me. Warning message has been coming on for past 60 days or so, progressively getting more frequent I receive a 'shift to park' message in telltale after I have shifted to park. At times, vehicle will not shut off until shifter is manipulated for several minutes. I have concerns that I cannot park vehicle in garage, if I cannot shut it off. GM is well aware of issue, but has yet to recall them. Dealer actually had replacement shifter in stock for a same day repair.. I was charged $778.98 for the repair, and GM's customer assistance center response to me simply was to file a complaint with NHTSA. My wife does not feel safe driving, as there is no guarantee vehicle will turn off. Dealer replicated issue when I brought to dealership. Dealer has replaced part and has them. Warning lights only appeared when problem reared itself, initially began about 60 days ago, but is not occurring on approximately 2 of 3 shut downs.

While driving the thermostat will go to zero and the steering assist is disabled. I have read a lot of forums that this is a known issue. The only way to reset it, so we have A/C is to disconnect the battery and it will last a day or two and do the same thing.

My 2019 GMC Acadia with 33,000 miles on it started to give me a notification to "Shift to Park" even though I had already shifted the vehicle into park. A "ding! ding! ding!" alarm wouldn't go off and the vehicle wouldn't turn off unless I repeatedly changed the gears until it read it was in park. This went on for a few weeks and got progressively worse. I read on a GMC forum that the vehicle could slip out of gear while driving and potentially cause an accident. My mechanic found the shifter assembly to be defective and replaced the entire Gearshift Lever Assembly. He said there was a plastic piece in the gearshift that snapped off and said this was an issue in the older models but thought GMC had fixed this issue by 2019. Unfortunately, I was past my 3 year / 36K mile warranty and had to fork over $1300 to have it repaired.

Our 2019 was repaired back in 2021 for a "shift to park" issue. This same issue is happening again after 2 years of being repaired. We see that there is a major issue with GMC vehicles and there have been recalls for this same exact issue. GMC Coleman, Lawrence NJ is refusing to fix problem under a recall. We would like this to be covered or reimbursed.

Code 0128 coolant temperature sensor failure triggered reduced lane departure assist

The contact owns a 2019 GMC Acadia. The contact stated while the vehicle was parked, she noticed that the engine caught on fire with no warning light illuminated. The fire was put out by the Chicago Fire Department and after the vehicle was inspected the cause of the fire was determined as a failure with the electrical system. A police report was filed with the Chicago Police Department and a report was provided. No injuries occurred and no medical attention was needed. The vehicle was not towed. The dealer was contacted, and the vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 65,000.

Mileage: 65,000

The contact owns a 2019 GMC Acadia. The contact stated while driving at undisclosed speeds, the "Steering Assist - Reduce Speeds" message was displayed, and there was a loud roaring sound coming from the engine. The contact stated that the check engine warning light was illuminated. The failure recurred while the heat was turned off in the vehicle. The vehicle was taken to an independent mechanic where it was diagnosed with a faulty temperature gauge. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 80,000.

Mileage: 80,000

In August 2021, I placed my vehicle in park and pressed the vehicle on/off button and received a message on the dashboard that stated "Shift to Park", even though the vehicle was in the off position. I was unable to turn my vehicle completely off (remained in auxiliary mode) and unable to lock the vehicle. I took my vehicle to a Chevrolet dealer who notated the issue was inspected and verified with a repair procedure under TSB 19-NA-206. The service record reads "This condition is caused by the park switch in the transmission control not pulling BCM signal low to electronically show part position. Removed and reinstalled transmission control, installed new shifter harness and added wire harness jumper". In February 2024, the repairs completed by the dealer failed again, and this time the entire shifter (transmission control) needed to be replaced. The TSB that GM has put forth does not "fix" the issue, just puts a temporary band-aid on the problem until the vehicle is out of warranty and the customer is forced to pay for the repairs themselves. Without the vehicle registering it is park, the vehicle stays active and the customer is unable to lock or secure the vehicle, putting the safety of the customer at risk. It is also unknown if the vehicle is actually in park, putting those around the vehicle in danger of getting run over.

Engine consuming extra oil due to failed piston ring. Also, may be the cause of a coolant failure code. Burning through excessive oil and check engine light came on. Also, prior to these warnings, I've felt hesitation when accelerating and when the car changes gears. I was told by a shop that I need a new engine. This causes a dangerous situation because the car could just stop working while driving or in traffic.

My 2019 GMC Acacia SLT would not go into park to allow me to shut off my vehicle. It ran for over an hour before it finally went into park. This was dangerous as I had a young child to pick up in a busy part of town and I had to leave it running to try to get help. With a 3 year old child this was crazy. This is not the first time it has done this. My car had a recall and whomever fixed it didn’t do it. I feel this needs to be fixed properly now.

Vehicle is constantly giving “shift to park” error. The steering mechanism has also been compromised, and the vehicle makes persistent jerking motions with accelerating. This could be quite dangerous.

For a few months I intermittently get an engine light on, the temperature gauge goes to zero, the AC stops working, and an error that driver assist in unavailable. This will happen for a fee days and return to notmal where everything is fine. This happens on and off again. I google searched this and it is a huge problem with GMC Acadias. I used an obdII scanner and get a P0128 coolant error when this happens even though the temperature is fine. I just recently went over the new car warranty and GMC will not tell me if this is covered or not.

Thermostat gets stuck, generally in open state. AC also is disabled in this condition, soft code (no MIL) mentions "limited steering available" and temp gauge on dash goes to 0. Hard code eventually comes (solid Check Engine light on the dash). Code, MIL, and temp gauge can be cleared and fixed by disconnecting battery negative terminal and reconnecting it, and it will run consistently for a while, though it will return. Online there are no thermostat modules for this engine available (3.6L V6, also in Cadillac XT6, Buick Enclave, and Chevrolet Traverse) showing that thermostat replacement is widespread. Online forum searches also describe widespread thermostat issues for this engine, at roughly $1200 per fix. A reliable thermostat is critical for long-term engine functionality, and should not need replacement at half of design life (~75-80k miles). Though this one tends to fail open instead of close, overcooling of an engine still could have its own issues, and failing closed could lead to engine overheating.

I’ve had 2 issues with the thermostat going bad. The official part is called the water outlet assembly that includes the thermostat. I’ve also had several others tell me they have had this issue.

While driving the temperature gauge shuts down completely to C - the check engine light comes on and a message appears on the dash saying "Steering Assist Reduce Drive With Care". Any air conditioning goes from cold to hot and the fan under the hood goes to high automatically and wont shut off. We have been informed that this is a known error that has existed for a long time now, with no recalls to date. I cannot schedule my vehicle for repairs yet because I do not have the money to pay for the repairs. They are saying that the placement of the thermostat and sensor, which need to be replaced in order to fix this problem, are located in a very difficult spot to get to. Saying that it will take upwards of 4-5 hours to get everything fixed, which increases the amount of money to fix this issue. My 2019 GMC Acadia just started doing this about 2 months ago and I have 54000 miles.

When I put my car in park and try to turn my vehicle off I get an error message saying “shift to park.” The problem is the car is already in park and I am unable to turn the off. I usually have to start the car back and drive back and forth before the car actually recognizes it is in park. Im concerned for my safety.

Gear shift notification problem. Unable to turn engine off after receiving "Shift to Park" message and the gear shift is visibly in the "Park" position. In addition, the doors would not lock. My wife was forced to stay in the unlocked running car in a store parking lot for 25 minutes, until the car just "turned off" on its own. Unsafe for a woman (or anyone) to have to do at 10:30pm. This puts drivers in a really vulnerable position. Vehicle taken to dealer Jan 30, 2023. Was told they were familiar with the problem.

Steering Assist reduced drive with care" displayed on screen when I was driving. The temp gauge stayed on C, Heat works fine, Happened for a few days.

Every time I go to turn off the engine it say shift to park and then I have to restart the truck and keep putting the shifter into park a couple of times for it to not happen.

About five months ago, my GMC Acadia started displaying a warning when I would put the car in park, and try to turn it off. The engine would shut off, but the electrical portion of the car would stay on, and would not turn off, because the warning displaying said "SHIFT TO PARK". I have tried every conceivable way to try to get this to go off, but nothing works. My car has stay on for upwards of two and a half hours, to the point where my battery died in the car and left me stranded. There have been numerous accounts of this, as I had read them on forums, yet still no resolution has been published. I have tried taking it to be inspected, but nothing ever comes up. I have two very small children, and if I were to be in public and be stranded because my car wouldn't turn off.... I would be livid.. Also, because of this warning, it prevents the doors from being locked. That is another major concern for me, considering the day in age we're in.

My vehicle would not turn completely off, I would have to start it about ten times before the warning sounds and the yellow light on the ignition switch would go off. I took my Acadia to Rod Hatfield Chevrolet Lexington, KY. I was told that there was an internal short with the transmission shifter, the shifter and harness would need to be replaced. considering that I purchased this vehicle new, and it has 39,793 miles I feel like it should have been covered under the warranty however, it cost me $903.3. I have an open case with GMC who suggested that I contact you to see if my Vehicle Identification Number could be added to for recall.

I purchased my vehicle brand new off the truck in march of 2020 with zero miles on it. Feb 2021 in negative degree weather, the heat on my vehicle stopped working. I called my local GM dealership and they told me they needed to diagnosed the vehicle. They had kept my vehicle for two weeks trying to diagnose the vehicle. It turned out to be the thermostat. they replaced that part on my vehicle. Now Dec 2021 I again have experienced the same problem this time it was in a blizzard. Dealership told me it cant be the same problem, however it will be another two weeks before they can get my vehicle in for service and do not have a loaner vehicles for use. I purchased a new vehicle with warranty as I have two small children and am currently pregnant.

DURING TAKEOFF WITH MODERATE ACCELERATION AROUND 1500-2000 RPM THERE IS AN EXHAUST DRONING/BUZZING SOUND FORWARD OF THE FRONT PASSENGER AREA. VEHICLE HAS BEEN TO DEALER TWICE, THE FIRST TIME THEY REPLACED THE ENTIRE EXHAUST SYSTEM, BUT AFTER 6 MONTHS THE SAME SOUND RETURNED. THE SECOND TIME THEY TRIED TO LOOSEN AND RETIGHTEN THE EXHAUST BUT THE SOUND RETURNED IMMEDIATELY AFTERWARD. THE DRONING SOUND IS MORE LIKELY TO OCCUR AFTER EXHAUST IS WARMED UP.

Mileage: 10,746

WHEN ACCELERATING THE VEHICLE EXHAUST OR ENGINE IS REALLY LOUD LIKE THERE'S AN EXHAUST LEAK.

Mileage: 39,998

TL* THE CONTACT OWNS A 2019 GMC ACADIA. THE CONTACT STATED THAT THERE WAS AN ABNORMAL SOUND INSIDE THE CABIN OF THE VEHICLE WHILE DRIVING WITH THE WINDOWS ROLLED DOWN. ADDITIONALLY, THE AUTOMATIC EMERGENCY BRAKING ACTIVATED WITHOUT DRIVER INPUT. THE VEHICLE WAS TAKEN TO RANCHO GRANDE MOTORS LOCATED AT 1404 AUTO PARK WAY, SAN LUIS OBISPO, CA 93405, WHERE THE CONTACT WAS INFORMED THAT THE ISSUE WAS COMMON WITH SIMILAR VEHICLES. THE AUTOMATIC EMERGENCY BRAKING FAILURE WAS NOT DUPLICATED. THE MANUFACTURER WAS NOT MADE AWARE OF THE FAILURE. THE VEHICLE WAS NOT REPAIRED. THE FAILURE MILEAGE WAS APPROXIMATELY 500. THE CONSUMER STATED THE DVD WOULD TURN ON IT. THE DEALER STATED IT COULD BE DUE TO A MISSING REMOTE THAT WAS NOT INCLUDED WITH THE VEHICLE. THE PARKING BRAKE WOULD ACTIVATE INDEPENDENTLY. THE CHECK ENGINE LIGHT WAS ILLUMINATED. THE STEERING AND ENGINE REDUCED POWER THE WARNING LIGHT ILLUMINATED. THE HEADREST DVD PLAYER DO NOT PLAY THROUGH THE SPEAKERS. THE WIRELESS PHONE CHARGER WAS OFTEN INOPERABLE. THE SECOND GEAR DOES THE NOT SHIFT PROPERLY. THE DASH AND RADIO PERIODICALLY LOSE POWER. THE WINDOWS MAKE A LOUD OBNOXIOUS NOISE WHEN ROLLED DOWN. *JS

Mileage: 500

AT 500 MILES PAST THE WARRANTY EXPIRATION THE RADIATOR DEVELOPED A CRACK ALONG THE TOP SEAM. THE DEALERSHIP SAID IT WAS A MANUFACTURES DEFECT AS THE VEHICLE WAS LESS THAN TWO YEARS OLD. GMC DECLINED TO REPLACE THE PART BECAUSE IT WAS 500 MILES PAST THE WARRANTY ALTHOUGH THEY DID NOT DENY IT WAS A MANUFACTURING DEFECT. I HAVE A GMC CASE NUMBER DOCUMENTING MY DEALINGS WITH THEM. I HAVE PHOTOS FROM THE DEALERSHIP SHOWING THE CRACKED RADIATOR, AS WELL AS AN EMAIL STATING IT WAS A DEFECTIVE PART. I HAVE THE RECEIPT AND I HAVE THE ACTUAL RADIATOR ITSELF. I NOTICED THE RADIATOR LEAKING ON MY GARAGE FLOOR WHEN IT WAS STATIONARY. THIS WAS 10 DAYS AFTER IT WAS LAST SERVICED AND THERE WAS NO ISSUE AT THAT TIME. THE DEALERSHIP SAID IT WAS NOT CAUSED BY IMPACT, BUT JUST THAT THE SEAM SPLIT AT THE TOP OF THE RADIATOR.*DT*JB

Mileage: 39,514

CAR AUTOMATICALLY SHUTS OFF WHEN DRIVING MULTIPLE OCCURRENCES OF THIS HAPPENING

Mileage: 5,500