The signal is on the canbus, this is low voltage through the twisted can high and can low wires. These joysticks do not need calibration. I have never seen this problem on low hour trucks. It sounds like a problem in the canbus wires, but you are not getting fault codes. The fact that there are no fault codes tells me the problem could be in the controller. The controller is the devise that reports faults and stores the faults. Have you checked the resistance in the canbus loop? It should be 60ohms. Maybe you are missing one of the resistors in the loop. If the reading is 120ohms you have an open resistor.