2020 GMC Acadia Complaints

STEERING,ELECTRICAL SYSTEM,ENGINE — Filed 04/09/2026

[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.

STEERING — Filed 02/01/2026

"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.

STEERING — Filed 04/22/2026

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.

POWER TRAIN,UNKNOWN OR OTHER,FUEL/PROPULSION SYSTEM — Filed 03/01/2026

I believe my car should be included in this recall. I've had the dealer check and they say it's nothing wrong with my car. 2020 GMC Acadia Fuel Pump Recall GMC has announced that 2781 vehicles have been affected by a Fuel Pump recall. General Motors LLC (GM) is recalling certain 2020 Buick Enclave, Cadillac XT5, Cadillac XT6, Chevrolet Traverse, and GMC Acadia vehicles. The fuel pump's jet nozzle may have a plastic burr remaining from the manufacturing process, possibly causing a blocked nozzle and an insufficient fuel supply to the engine. Insufficient fuel supply can result in an engine stall without warning, increasing the risk of a crash. 2020 GMC Acadia Recall Fuel Pump GM will notify owners, and dealers will replace the fuel pump module. The recall began November 16, 2020. Owners may contact GMC customer service at 1-888-988-7267, Buick Customer service at 1-866-608-8080, Chevrolet customer service at 1-800-222-1020 or Cadillac customer service at 1-800-458-8006. GM's number for this recall is N202314760.

POWER TRAIN,ENGINE — Filed 06/22/2026

Thermostat and cooling sensor went out on my car. GMC issued a special coverage bulletin for 2021 Acadia since it's a widespread issue but not the 2020 (mine) which is also a widespread issue looking online. The repair is over $1000 and should be covered!

ELECTRICAL SYSTEM,ENGINE — Filed 04/01/2026

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

ELECTRICAL SYSTEM,EXTERIOR LIGHTING,FORWARD COLLISION AVOIDANCE — Filed 05/01/2026

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.

ENGINE — Filed 04/15/2026

Coolant temperature sensor failed - it is still in the engine. the fan stays on high all the time. And the AC does not want to turn on. The car is extremely hot to drive in during the summer months. I have to transport persons who are seniors and in their mid 80s. It is not safe to drive this car in the summer. I can't tell if its over heating or what is happening. The coolant temperature gauge does not work. The dealer said my car is out of warranty and that the AC will not start until the sensor is replaced. I said that it has less than 50,000 miles. They will not help me. The vehicle has not been inspected anyone other than the service mechanic. The engine light start coming on about a month ago. I drove first to an autoparts store to see if they could help. this is the first time I learned that it could be a bad sensor.

ENGINE — Filed 05/15/2025

A common issue in GMC vehicles (particularly 2017–2020 Acadias) is a "Steering Assist Reduced" warning message triggered by a failed engine coolant thermostat that gets stuck open. This causes the engine to run too cold (P0128 code), causing the computer to reduce steering assist (which is dangerous) and run fans on high, also the air conditioner fails. I have seen many complaints about this and it seems to be a manufacturers problem. GMC put out a repair bulletin for the 2021 models with this issue. It's time to address these other years.

ELECTRICAL SYSTEM — Filed 10/01/2025

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