2020 GMC Acadia steering problems

Filed Oct 4, 2026 · Steering · OH

Thermostat housing failed. Got the message of "Steering Assist Is Reduced – Drive With Care". Have seen this numerous times in message boards. Has been reproduced. Safety is put at risk with the steering assist reduced. Mine happened on an highway.

Filed Sep 30, 2026 · Engine, Steering · AL

Engine thermostat not functioning properly, therefore the display stayed on cold and would not show temp. It also cause the fan to run fast to cool engine. The AC would not cool and reduce power steering assist error message comes on. This is a known problem by GM and there is a recall for this issue on many of these vehicles, other GMC and Cadillac vehicles. Our vehicle should be added to the recall list!

Filed Aug 23, 2026 · Engine, Steering · NY

Received a power steering reduced notice when starting the car, noticed shortly after driving the temperature gauge had not moved from its resting position. A few trips later it still had not moved and the check engine light came on. Mechanic looked at it said it may be a sensor quoted $1k to fix. A few days later it randomly started working and the light went off so I did not have it fixed. About 4 months later the same code displayed on the dash with the same issues. This time I noticed the ac would not work either it only blew out hot air. Also the fan under the hood turns on as soon as the car is started. Been about 3 days and it started working again out of nowhere.

Filed Jul 12, 2026 · Electrical, Engine · CA

[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. the federal safety agency should investigate whether additional 2020 vehicles are experiencing the same failure sequence and resulting safety risk.

Filed Jul 8, 2026 · Steering · MN

"Steering Assist Is Reduced – Drive With Care" warning appeared while the vehicle is in motion. This may require increased steering effort and could affect a driver's ability to respond to changing traffic conditions. Any steering-related warning that appears unexpectedly while driving deserves serious attention. P0128 code was shown. The cause was a faulty thermostat housing assembly and needed to be repaired. This is an extremely common issue in this vehicle across many years and needs to be investigated.

Filed Jul 7, 2026 · Steering · LA

Steering assist reduced is the warning. The AC will no longer work and the fan runs constantly. From what I’ve read, it is a popular problem for Acadia owners and the thermostat and sensor has to be replaced. We have not been able to replace ours yet because of the cost.

Filed Apr 30, 2026 · Engine, Fuel system · 61,699 miles · ID

The contact owns a 2020 GMC Acadia. The contact stated that while driving the vehicle, it stalled after initially adding fuel. Even though the reading indicated there was 1/8 of a tank of fuel. The fuel gauge failed to move. The thermostat was stuck open. The electric steering was not working properly. The engine light was illuminated. The traction control was turned off. The contact stated that the failure was related to the federal safety agency Campaign Number: 20V639000 (Fuel System, Gasoline). The contact stated that he was a master mechanic. The contact called the local dealer, but the vehicle was not diagnosed or repaired. The contact called two other local dealers, Tadd Jenkins Chevy 409 Farnsworth Way, Rigby, ID 83442, and Smith Chevrolet. Address: 3477 Pioneer Dr Suite 200, Idaho Falls, ID 83402. The manufacturer was contacted, but no assistance was provided. The failure mileage was approximately 61,699.

Filed Apr 15, 2026 · Steering · NY

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!

Filed Apr 4, 2026 · Steering, Transmission · PA

Thermostat

Filed Mar 17, 2026 · Electrical, Steering · 47,000 miles · VA

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.