2017 GMC Acadia Steering Problems

Steering assist is reduced

On [XXX] my 2017 Acadia Denali started driving poorly and a steering assist reduced message appeared. I had O'Reilly scan for error messages and they were: P0128 and P0826-00. The dealership confirmed that they would need to replace the thermostat. The Buick GMC Beaverton technician made a video of my vehicle: [XXX] My safety was put at risk due to the risk of my steering going out. My car intermittently was having trouble engaging in driving (it randomly acted like it was not firing, it was "jerking"), I heard my cooling fan come on immediately the next day when started my car to drive it to the GMC dealership. I feared that my car would just die going over a mountain pass without cell coverage. On [XXX] I had the same steering assist reduced message and then replaced my thermostat at 39,228 miles. I will need to replace this again, 37,638 miles later. The GMC service technician mentioned that this is a typical problem for my car, and I have discovered a 2022 Acadia recall for their thermostats. Please extend this recall to include the 2017 Acadia. The component was not inspected by the police or insurance rep (yet), but it was inspected by the GMC dealership and O'Reilly veri scan. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Vehicle keeps intermittently coming up with "Power Steering Reduced: Drive with Care," during this my steering is perfectly fine, however my A/C stops blowing cold air, the temperature gauge stops working and my engine fan is running constantly. This is obviously a well known issue since googling that warning and my vehicle it comes up with the issue and what the cause is. Which the cause is from the thermostat remaining open and allowing coolant to run through the system, even when the vehicle is not overheating. I just bought this vehicle used from my local dealership and am surprised that GM has not recognized this is an issue affecting numerous vehicle. This should at the very least be put as a warranty covered issue!

While driving at highway speeds, a warning appeared on the Driver Information Center (DIC): “Steering Assist is Reduced – Drive with Care.” Simultaneously, the temperature gauge was stuck on “C,” the radiator cooling fan ran at high speed, and the air conditioning stopped blowing cold air. After researching the issue, I discovered that these symptoms are commonly linked to a failing thermostat—a known and widespread problem with GM’s 3.6L LGX engine. Unfortunately, replacing the thermostat on this engine is not a simple repair, often requiring significant labor and cost. The most concerning aspect is the loss of steering assist, which poses a serious safety risk, especially at highway speeds. Given the frequency of this issue across many GM vehicles, it’s clear that this is a defective part and not an isolated incident. GM should take responsibility and cover the cost of repairs for affected vehicles. This is not just a mechanical failure—it’s a safety hazard that deserves immediate attention. I'm attaching a picture of the message as well a paid repair invoice from the work the dealer performed to replace the thermostat on my vehicle.

The contact owns a 2017 GMC Acadia. The contact stated while driving at an undisclosed speed, the contact became aware that the steering wheel was inoperable, with the message “Steering Assist Reduced” displayed. The contact stated that the steering wheel was loosened and became difficult to turn. The vehicle was able to restart. The vehicle was taken to the dealer where it was diagnosed that the thermostat coolant sensor had failed and needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and referred the contact to the NHTSA Hotline for assistance. The approximate failure mileage was 80,510.

Within a day of taking possession of the car, September 20, 2024, with odometer reading 76,352 , warning message in instrument cluster appears stating action required “steering assist is reduced, drive with care”. Following day, A/C stop working while driving. When park, I can hear radiator fan, running full speed (louder than normal). While driving at night, headlights are not bright, specially the high beam. On September 23, 2024, took it back to dealership I purchased the vehicle. They have the vehicle in the shop to fix the issues. Vehicle was ready for pick up September 27, 2024. September 29, 2024. Message in instrument cluster screen re-appear stating “Action required, steering assist reduced drive with care”; check engine light came on, remote start key not working, A/C stop working again, radiator fan running full speed and loud , Headlights are still not bright, Infotainment screen glitching, will not stay in home button and making clicking sound. Went back to dealership so that they can fix it. Diagnostic code : P0128. They were able to have A/C working when I left the shop. and no messages on the instrument cluster. Following day, I have all the same issues I have before. My appointment to come back in to the shop to fix the thermostat issue I was October 10, 2024, on October 9, additional problems occur on top of the issue I am having. While driving and accelerating multiple lights on the instrument cluster screen appears on top of other issues and car decelerates. The check engine light came on, steering assist reduced drive with care , parking brake, car stability comes on and message stating engine power is reduced. This happened while driving on a highway at night on my way to work. I had to have the vehicle towed to the dealership..

The contact owns a 2017 GMC Acadia. The contact stated while driving at an undisclosed speed, the power steering assist warning light illuminated. The contact stated that the warning light then turned off independently. In addition, the contact stated that the air conditioning failed to function as intended and the interior of the vehicle became extremely hot. The vehicle was taken to the dealer; however, the failure was not duplicated. The contact stated the vehicle was taken to the dealer in 2024 for the failure, and the contact was informed that the power steering assist feature had failed, and the software needed to be updated. The vehicle was repaired; however, the failure reoccurred. The manufacturer was made aware of the failure. The contact was advised to contact the NHTSA Hotline to report the failure. The contact was advised to take the vehicle to the dealer for a diagnostic test, and a case number would then be provided. The failure mileage was unknown.

Steering Assist is Reduced due to a faulty thermostat

I believe my vehicle has a software issue, the temperature gauge will read cold, I will get a “Steering assist reduced drive with caution” message, my A/C stops working, and the radiator fans come on full blast the moment you start the car because the temperature can not be read. I have read online forums where others are having this same exact issue. Resetting the codes seems to temporarily fix the issue, but it comes back within roughly 2 weeks. This vehicle has not even reached 60k miles yet.

Vehicle will randomly drop into a lower gear which causes the engine to rev up, then a warning light comes on indicating that the steering assist and ABS system are offline. Not what you want to have happen when driving 70MPH on the highway. Problem has been ongoing for ytears and GMC insists it is a transmission problem but another thing I have noticed whenever it happens is that the battery voltage increases. Seems like GMC shipped these cars with weak alternators which would explain the myriad electrical problems this vehicle and others like it have had.

• Steering and Air conditioning • Possible death and heat stroke •Yes •No •No, just came on all of a sudden

Sudden loss of power steering due to steering pump failure. Wife was turning onto a busy road and the power steering went out causing her to almost hit oncoming traffic on the other side of the lane. Very serious and upsetting experience. In doing so research it appears this has been an ongoing issue with this vehicle and the previous model. Life safety issues such as this should be recalled at once before someone else’s wife and children are killed. Vehicle is currently at shop for replacement.

Steering assist reduced, drive with caution message displayed. Steering wheel sticks when turning. Apparently caused by a faulty thermostat and/or temperature sensor. Had both replaced several months ago. however, both the message and symptoms have returned.

1. COULD NOT PUT CAR INTO PARK OR TURN OFF. CAUSED BATTERY TO BE DEAD AS IT WOULD NOT TURN OFF WHEN PUT INTO PARK. 2. STEERING WHEEL LOCKED AND JERKED REPEATEDLY. COULD NOT TURN INTO PARKING SPOT. THE STEERING WHEEL HAD A MIND OF ITS OWN AND COULD NOT STOP THE JERK. IT IS DANGEROUS AND SCARY ! 3. AT NIGHT, THE HEADLIGHTS DO NOT LIGHT THE ROAD. IT IS AS THOUGH THERE ARE NO LIGHTS AT ALL. IT IS DANGEROUS TO NOT SEE THE ROAD AT NIGHT BECAUSE HEADLIGHTS DO NOT GIVE APPROPRIATE LIGHTING.

My vehicle has serious issues that from my research seem to be a common problem/manufacturer defect experienced by other owners of this model. I believe the defect/issue is an electrical problem. While driving, the vehicle will often have problems using it's automatic transmission. It ranges from "rough" shifting (where the car jerks while shifting gears) to situation where the vehicle fails to shift gears completely leading to the RPMs shooting up. The cars power steering and traction control system also simultaneously fail. This leads to a dangerous situation when on highways etc This issue simultaneously causes all of the warning lights on the dashboard to light up while displaying the following messages on screen "Service stabilitrak" & "steering assist reduced -drive with care" & "service brake assist" & "service parking brake". The gauges also stop responding/reflecting accurate info when this happens. I have a video of what this all looks like. This has been on ongoing intermittent problem pretty much for the entire life of the vehicle. GMC informed me that they had never heard of this when I inquired about it a dealership but searching online makes it incredibly clear that this is an extremely widespread issue that they are aware of. I have also attached a file that has a list of all error codes detected by me for this vehicle.

P0128 Apparently what happens when the temp sensor on the T-Stat housing goes bad it sends a signal to the ECM that the engine is overheating, causes the temp gauge to peg to "C", shuts down A/C Compressor Clutch engagement to not exacerbate the Overheat condition and super speeds the cooling fans. Of course it's a false flag warning and the engine isn't actually running hot. At the same time a signal to the ECM also tells the Power Steering Rack that it's Super Cold out and the lube in the steering system may freeze up causing loss of steering assist. NHTSA 17-NA-158 - MAY 2017 Needed to have Thermostat and Temperature sensor replaced. Was quoted by two dealers $1400-$1700. Very deceiving for GM to have SEVERAL "tech bulletins" advising their techs how to properly diagnose this common "error"... but it's not a recall so they won't foot the bill for what is clearly a defect. Car has only 59,400 / 2017 GMC Acadia All Terrain

I brought this car from STOOPS and have been having this same issue since I received this car in March of 2021. Check engine came on within two weeks of me getting this car. The Intake air pressure measurement system MAP sensor and MAF sensor on my 2017 GMC Acadia which is causing other issues. My car is only at 100k mikes and I shouldnt be having the same issue. The MAP sensor was replaced in July of 2021. Here it is a year later and my check engine light keeps coming on and saying the same thing which is causing all these other issues to happen such as steering power system reduced which driving. Notifications about of transmission and engine issues because of Intake Air Pressure Measurement System. Every time I take it to stoops they have it for a couple days and I’m out of a car which means no transportation for work and within 10 days after I get it back the same issue appears. The car sounds like it’s going to shut off at any given time I’m driving. It shutters while at a light or in a restaurant line. It drives smooth but when I shut the car off it makes a whiny noise sometimes. I don’t feel safe driving myself and my kids in the car when different things come up all because of this intake air pressure measurement system issue

The steering control system stops working abruptly , it happened to me numerous times while making a turn. It almost caused an accident and it made my wrist hurt from trying to move the steering wheel in order to not crash.

The vehicle makes a clunk and pop noise when making turns and upon acceleration and deceleration. Both dealer and repair shop could not visually locate the problem after checking. Suggested the problem was internal. Vehicle purchased March 2022 with 63,500 miles.

We were receiving a message stating steering reduction. Turns out the thermostat sticks open and the electronic control module reset was a temporary fix. We had the thermostat replaced and the issue hasn’t happened again. Steering issues should be a safety issue and be considered for recall. Your thoughts please.