Case IH 4151:

Check for other active EHR error codes: make a note of any other codes, clear them, and test the system for normal operation

Check hydraulic pressure: verify the regulated hydraulic pressure (low pressure standby and high pressure standby) to ensure the valve is receiving the correct operating pressure

Inspect the wiring harness and CAN BUS: check the wiring between the rear remotes and the central controller, ensuring the connectors to the #4 EHR valve are connected, undamaged, pins are in the correct position, and the fit is tight