wa-480 komatsu transmission cut off problem

WA 480-6 Komatsu .We are having a problem with the transmission cut off,works a few minutes then stops working.Getting code DHT1KX. Komatsu dealer changed cut off sensor,by passed harness from controller to sensor, changed both toggle switches,tried a new controller with still same end result. We are at our wits end. If any one has an opinion I would sure love to hear about