The contact owns a 2012 Ford Fusion. The contact stated that the A/C unit failed to operate as needed, causing the cabin of the vehicle to become hot while driving. There was no warning light illuminated. The vehicle was taken to a local dealer, where the vehicle was diagnosed, and the contact was informed that the evaporator temperature sensor was faulty and needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 143,000.