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 âSteering 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.