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Steering Assist is Reduced Drive with Care

76098 Views 50 Replies 31 Participants Last post by  JayTee2019
I have a 2018 Acadia Denali & it is showing the Steering Assist Error Message which I believe is something with the Thermostat. Can someone please quickly explain the cause of this problem & what the Solution is? I want to be able to present it to the dealer if they try and tell me the problem I'm having is something else.


Thank you,

Dan
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Was issue fixed after the new thermostat?
No more problems since my thermostat was changed.
I am having this issue now with my 2019 Acadia. Were you able to get the issue resolved?
I had the same issue. I took it to my dealer, they are going to replace the whole thermostat box. He said it was a common issue and it is covered under my powertrain warranty. Only problem is that the product is 1-2 weeks out.
I just replaced the battery and still am having this error message. I have a 2018 Acadia. Did they give you an estimate for the thermostat?
According to my dealer this should be covered under the powertrain warranty. Mine is at the dealer right now getting fixed.
Having issues with my 2018 Acadia. Steering assist warning coming on then the AC quits on me In the heat of Florida. Next my engine light comes on. I have no issues with the steering getting hard or difficult to drive. So I’m pretty sure it’s has to be a issue of some kind with something else.
but what I’m seeing here is this issue has been happening in almost all years of this SUV. Why has there not been a recall on this.
when we bought this vehicle we were never offered a extended warranty. Our local dealership said we can still get one. It is going to run us $4000 for the warranty. But reading all the issues every One is having.Along with all the past issues we have had makes me think it will be worth it.
my husband keeps resetting the car by disconnecting the battery each time the warning comes on and the AC quits. And it solved the problem for a day or so. The warranty will be good for 4 years. Does anyone else have a extend warranty and do you feel it has been worth the expense. We are 2 months out of our 60,000 mile warranty. So no more warranty left on our car. And reading the price the one person said they charged him to replace his thermostat tells me it might be a good move.
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Have you been able to resolve this problem? This same thing has been happening to me on and off for the past 8 months. Just when I think it’s fixed it happens again. If the error isn’t happening when I bring it into the dealership they can’t fix it but we live almost 2 hours away from one.
I know exactly what you’re saying. We have a multiple in our car and he’s changed his day to come here because the warning is up and then when he gets here and he turns the engine overthe warning light is gone
. I’ve been disconnecting a battery and hooking it back up after about 10 min,and when we turn it over it seems to solve the problem temporary I’ve been reading a lot and a lot of people are changing thermostat and that seem to be responding to the problem so that’s the next thing we will be doing
I have a 2018 Acadia Denali & it is showing the Steering Assist Error Message which I believe is something with the Thermostat. Can someone please quickly explain the cause of this problem & what the Solution is? I want to be able to present it to the dealer if they try and tell me the problem I'm having is something else. Thank you, Dan
i had the same problem and it is the thermostat
Can’t believe that was it! 2019 Acadia SLT2 and exact same problem out of nowhere: “Steering Assist is Reduced Drive with Care”, and at the same time the AC started blowing with no cold air at all- (it went to full power without touching it.) Cleaned the terminals, including fuse terminals on top of battery. Waited 15 mins and everything worked perfectly fine.
Can’t believe that was it! 2019 Acadia SLT2 and exact same problem out of nowhere: “Steering Assist is Reduced Drive with Care”, and at the same time the AC started blowing with no cold air at all- (it went to full power without touching it.) Cleaned the terminals, including fuse terminals on top of battery. Waited 15 mins and everything worked perfectly fine.
The problem will likely return.
i had the same problem and it is the thermostat
Ok can some one please tell use where the thermostat is located in a2018. My husband has always worked on our cars. But we can not find a Haynes book on this car. It seems they don’t make it past the 2017. If he could locate it could change it out.
Ok can some one please tell use where the thermostat is located in a2018. My husband has always worked on our cars. But we can not find a Haynes book on this car. It seems they don’t make it past the 2017. If he could locate it could change it out.
Haynes manuals have become pretty much worthless on modern vehicles. You need either a copy of the factory service manual or a subscription to ALLDATA.com
Ok can some one please tell use where the thermostat is located in a2018. My husband has always worked on our cars. But we can not find a Haynes book on this car. It seems they don’t make it past the 2017. If he could locate it could change it out.
Check this thread below and the 2 videos in it.

It lists the parts needed also and the 2nd video shows some hints to reduce what is needed to remove and replace the thermostat.

Read the thread below . . . but here is the 2nd video I referenced above:


Had the same issue, no A/C, Power Steering Assist Reduced/Disabled notification, Fan running all the time, Engine Temp at 0, and P0128 Code.
Had to go to the dealer to get the following parts
Manifold Gaskets x6 Part# 12648665
O-rings for the 2 return lines x2 Part#12648547
Thermostat assembly and water pipe Part# 12678779
Engine Temperature Sensor (might as well replace this $12 part at the same time) *This one you can get anywhere Part# TX281
Cost $276
If I had brought it to a shop - $1627.00
Took roughly 3-4hrs to complete
Best videos for walk through
I had to unseat the ground on the battery and reseat (reset the system) - Problems resolved.
The cause is that the thermostats are opening too early and allowing the engine to not warm up to proper operating temp - this causes the control module to suspect that the coolant temp sensor is inaccurate and there for reduces stress on the coolant system and other sub systems by turning cooling fans on high, and reducing electrical draw by offering less electric steering assist - it won't always set a hard code, but will always have a "pending" status codes for p0128 - clear the codes and everything goes back to normal until the conditions are met to set the code again - we have replaced a few of these thermostats in the last couple months on the LGX high feature 3.6 - In our market/region, going rate for that job is about $1100 out the door.
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Currently having the same issue with my 2017 Acadia Denali, so annoying.
I have been having the same issue since March 2022. It cleared on its own for about six months, then it came back. I changed the battery and it was fine for about two months. I have been disconnecting the battery and it is fine for a few hours, days, or weeks, but I can't figure out what is triggering this problem. I finally gave in and took it to our local mechanic to get a new thermostat and sensor put in. Initially quoted $1,100, but they just called saying they recommended changing some seals and a fuel pipe in the process of putting everything back together, which will be an additional $300. I hope this solves it, or I am going to be a pissed off puppy! The fact that this is such a common issue and GMC has not come out with a formal recall is ridiculous. I am keeping all my receipts in case they do ever recognize their mistake and I can claim a refund.
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Hi All,

I have same issue on my 2017 Acadia Denali , current odometer 112,891 kms / 70,147 miles.
Took it to local GMC Dealer Service centre. They are saying is a "big" job with 6 hours of work required.
They are saying the "Thermostat is stuck" and is blocking the engine coolant from flowing correctly through engine.
And due to the location of thermostat box, it will require them 6 hours to replace and they will also need to flush out and refill engine coolant. They mentioned that I was lucky that I didn't drive a lot with this condition as there was possibility of engine overheating and possibly blowing up.

Wanted to check if C$2250.00 + tax , seems genuine for this job?
I am reading folks talking about $1400 out-the-door, thats like $1866 CAD.
This is GMC dealership located in Metro Vancouver, CANADA.

Is it valid explanation that engine could overheat due to this issue?
I read through this thread and no where anyone has talked about engine overheating. I took my car to dealership right after warning message came, so not sure if engine is heating due to this.
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Hi All,

I have same issue on my 2017 Acadia Denali , current odometer 112,891 kms / 70,147 miles.
Took it to local GMC Dealer Service centre. They are saying is a "big" job with 6 hours of work required.
They are saying the "Thermostat is stuck" and is blocking the engine coolant from flowing correctly through engine.
And due to the location of thermostat box, it will require them 6 hours to replace and they will also need to flush out and refill engine coolant. They mentioned that I was lucky that I didn't drive a lot with this condition as there was possibility of engine overheating and possibly blowing up.

Wanted to check if C$2250.00 + tax , seems genuine for this job?
I am reading folks talking about $1400 out-the-door, thats like $1866 CAD.
This is GMC dealership located in Coquitlam, BC, CANADA.

Is it valid explanation that engine could overheat due to this issue?
I read through this thread and no where anyone has talked about engine overheating. I took my car to dealership right after warning message came, so not sure if engine is heating due to this.
Generally, this condition occurs because the thermostat may stick - - -OPEN . .. . so the engine control computer see it as not getting to a warm enough temperature in a certain amount of time.
You can reset this error by disconnecting the negative battery cable waiting a minute and connecting it back up. Or. .have someone with a shop reset it with a device that plugs into the Acadia under the dash.
Some also think it is just an electrical glitch since the coolant temperature is correct, and the engine computer interprets it as incorrect. . . . witch causes the messages you are seeing.
Had the same problem back in June and before message would come on then go off then it came on consistently air conditioner shut down. Research the issue tried a few fixes the one I found at work or my problem was the battery terminals need to be cleaned and tightened. Once that was done the problem was fixed so far the last three months have been good.
Thank you for saving my life! I've had this issue for 2 years and couldn't figure it out.
Add mine to the list. 2017 with 58k on it. I tried the battery terminals and it worked for a month. Now I guess I'm tearing this thing apart to replace the themostat and temp sensor.


Mine just randomly started with EVAP codes too. I had planned to drive this thing for a long time but it's getting irritating with issues under 60k miles.
Okay, my 2017 Acadia just started giving me the same message. Driving assist reduced…blah,blah,blah. So I googled everything I could find about it. Then tried cleaning the battery terminal and , weirdest thing, it all started working fine. I’m not sure if it will continue working. But at least for now it looks good. Hmm?
Wife’s 2017 Acadia Denali ( 34,000 miles ) has had this issue for the last 8 months. It first came on while we were on the freeway for about 45 min. Cool temp gage drops to cold, AC blows Luke warm and steering asist doesn’t work, fan kicks on high.Cleaning the terminals and disconnecting the negative one for about 5 minutes has been resetting the issue and clearing the code. my wife drives less than 10 miles to work and very rarely makes her way on the freeway, so for that reason the message rarely comes on. What my wife has noticed it comes on after about 45 minutes of freeway driving, When she has to drive to clients out of town. Called local GMC dealer and they are recomending replacing the thermostate housing but first to bring it in the next time the message comes on to check the code being thrown. Keep you guys posted!
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