2020 GMC Acadia Electrical Problems

[Symptom & Safety Hazard] While driving my 2020 GMC Acadia 3.6L V6, the Driver Information Center displayed the warning: "Steering Assist Reduced, Drive With Care" (SARDWC). Steering effort increased abruptly, the engine temperature gauge dropped to cold/zero, and the HVAC system lost air-conditioning function. The warning and reduction in steering assist presented a safety hazard and increased the risk of a crash. [Diagnostic Findings] Vehicle diagnostics identified DTC P0128 - Engine Coolant Temperature Below Thermostat Regulating Temperature. A GMC Certified Dealer technician diagnosed a failed engine coolant thermostat housing assembly. [Manufacturer Information] GM documentation links DTC P0128 and invalid engine coolant temperature signals to the "SARDWC" condition. GM Bulletin 17-NA-158 states the “SARDWC” condition is caused by an invalid coolant temperature signal and the steering module relies on coolant temperature information for steering-assist compensation. GM bulletin PIT5967 directs technicians to diagnose and repair DTC P0128 when the warning message is present. In Oct 2025, GM issued N252508350 for 2021 Acadia vehicles equipped with the 3.6L LGX engine due to an engine coolant thermostat condition. My 2020 Acadia is part of the same generation vehicle platform and is equipped with the same 3.6L LGX engine. It experienced the same thermostat-related failure symptoms, including DTC P0128 and the "SARDWC” warning. [Reason for Complaint] I am filing this complaint because a thermostat-related cooling-system failure resulted in a steering-assist warning and reduction in steering assist while the vehicle was being driven. Moreover, GM issued N252508350 for 2021 Acadia vehicles equipped with the 3.6L LGX engine due to the same engine coolant thermostat condition, yet similarly affected 2020 Acadia vehicles are not included. NHTSA should investigate whether additional 2020 vehicles are experiencing the same failure sequence and resulting safety risk.

NHTSA ID

11749841

Incident

Apr 9, 2026

Thermostat issue causing check engine light as well as steering assist to be turned off. Fan constantly runs. Reset code and immediately is fine again for anywhere from a day to weeks but then happens again. Car is just out of warranty but seems to be common occurrence as there is a service bulletin for the 2021 model

NHTSA ID

11741177

Incident

Apr 1, 2026

Back up camera randomly stops working (black screen-completely gone, or blue screen). Dash will randomly dim on its own and does not go back to normal unless car is shut off and turned back on. adaptive cruise control will disengage for no apparent reason. stabilitrak will flash on screen but no other indicators or reasons; nothing happens with car. Occasionally the blind spot mirror lights will not light up when vehicle is present.

NHTSA ID

11738492

Incident

May 1, 2026

My backup camera does not work when engaged in reverse, causes the radio to turn off and on.

NHTSA ID

11734822

Incident

Oct 1, 2025

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.

NHTSA ID

11732081

Incident

Feb 20, 2026

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.

NHTSA ID

11724868

Incident

Mar 6, 2026

Mileage

47,000 mi

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

NHTSA ID

11724079

Incident

Feb 23, 2026

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.

NHTSA ID

11714468

Incident

Oct 1, 2024

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 ID

11701183

Incident

Oct 16, 2025

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 ID

11659505

Incident

May 7, 2025

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 ID

11646575

Incident

Feb 9, 2025

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 ID

11627362

Incident

Oct 20, 2024

Transmission gave out

NHTSA ID

11610991

Incident

Aug 23, 2024

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!

NHTSA ID

11608328

Incident

Jul 31, 2024

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)

NHTSA ID

11598664

Incident

Apr 16, 2023

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.

NHTSA ID

11592258

Incident

May 1, 2024

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.

NHTSA ID

11552490

Incident

Oct 16, 2023

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

NHTSA ID

11551153

Incident

Oct 20, 2023

While driving the vehicle goes into Automatic Braking. It has stopped me while I'm driving or it will make a loud scrubbing noise as if I've hit the brakes quickly. It has happened over 15 or more times. I've taken to dealership and they are not very responsive to check into the issue I am having. It is a danger to me if I am on the Interstate with vehicles traveling at a high rate of speed.

NHTSA ID

11508507

Incident

Feb 15, 2023

The vehicle’s lock/unlock feature is inoperable either via the buttons on the door inside the vehicle or via the key fob. There is no manual way to lock/unlock the vehicle from inside the vehicle. Driver and passengers could only exit vehicle via rear lift gate or thru the vehicle windows. Should driver or passengers have had mobility issues or not been able to crawl through the vehicle to exit via the tailgate, they would not have been able to exit the vehicle in the event of any emergency. Incident has happened on at least 3 separate occasions.

NHTSA ID

11493926

Incident

Nov 16, 2022

Center console display does not start when you start vehicle. Stays blank! This happens occasionally. Sometimes restarting will fix, other times not. There is no rear view camera when this happens. Not sure what else is affected, such as backup warnings.

NHTSA ID

11477176

Incident

Jul 23, 2022

navigation system stops working / all cameras stop working give a triangle with exclamation in the middle / radio also shuts down

NHTSA ID

11475437

Incident

Jul 1, 2020

I noticed for months it was downshifting hard but transmission department was backed up I scheduled in September for an appointment October 26 and that morning I received a call to reschedule because they were still behind and had another appointment for November 10th. The morning of the incident 1st it did not want to start it would only turn over. When it started the check engine light was on (I called service he asked if I could drive it and told me to bring it in). Within 10 miles of driving, the car started to slow down. When I pressed the gas the RPMs would go up but the car would not accelerate. I was on the interstate so I started to coast to the side. When I got to the other side of the rumble tracks the fuel gauge warning came on saying no fuel (even though I had half a tank which was verified through the service department) and the car came to an abrupt stop. Had I not gotten over when I did the car would have stopped on the highway. I tried to turn it on to move it farther off the road and it would not. It started to just turned over like it did when I originally tried that morning (all over the occurrences happened while I was on the phone with Adrienne who i contacted through the gm help line).

NHTSA ID

11439733

Incident

Nov 4, 2021

The vehicle was purchased brand new from Serra GMC in Washington Michigan in April 2020. It has been back to the dealer 5 times for the same issue, with another 4 times that it was not taken into dealer! Reoccurring issue involves the instrument cluster, All gages and visual indicators go to zero (speed, tach, fuel, temp, etc...) as well as getting a notification that the traction control is disabled, the ABS is disabled, cruise is disabled, and other electronic aid. This happens at highway speeds and to loose all function is a safety concern, it is not repeatable and happens randomly but it is the same issue. The dealer claims to fix the issue but it always comes back. GM has told me to accept the issue as its not detectable however this is unacceptable as it puts my family at risk. I have videos of the instrument cluster going to zero but its to big to attached - I can provide it if you contact me or tell me how to share it

NHTSA ID

11434839

Incident

Oct 20, 2020

BRAND NEW VEHICLE. PURCHASED ON 10/30/2020. FRONT COLLISION KEEPS FLASHING A RED LIGHT IN THE TOP OF DASH THAT SHOWS UP IN WINDSHIELD. THIS HAPPENS WITH NO OTHER VEHICLES ON THE ROAD AT RANDOM TIMES. WHEN THE VEHICLE NEEDS TO STOP OR WARN YOU IT WILL NOT. IT WILL JUST LET YOU HIT A PEDESTRIAN OR ANOTHER CAR. WE NOTICED THAT THE SAME THING IS HAPPENING WITH THE REAR SAFETY CROSS TRAFFIC.

NHTSA ID

11383475

Incident

Nov 10, 2020

Mileage

55 mi