Case IH 4125 – EHR (Electronic Hydraulic Remote): Rear remote no. 2 - internal position sensor faulty

This code indicates that the control module is receiving an out-of-range, implausible, or missing signal from the internal spool position potentiometer (transducer) located inside the #2 rear electronic hydraulic remote (EHR) valve.

• Magnum
• Maxxum
• Steiger T4B
• MAXXUM T4E
• VESTRUM CVX
• Magnum Series 4
• Magnum MX
• Steiger
• Puma

1. 1

   Check for Associated Codes: Look for other EHR error codes (e.g., 4126, 4127) that might indicate a broader voltage or CAN-bus issue. Make a note of them, clear the codes, and test the system to see if 4125 returns.

2. 2

   Wiring and Connector Inspection: Inspect the wiring harness between the #2 rear remote valve pressure/position sensor and the ECU. Ensure the connectors are fully seated, not damaged, and that the pins are tight and in the correct position.

3. 3

   Continuity Test: Perform a continuity test on the wiring harness between the valve sensor and the ECU to rule out an open circuit or a short to ground/power.

4. 4

   Calibration Check: Attempt to recalibrate the EHR remote valves via the tractor's display or A-post monitor. Sometimes a valve that has lost its neutral setpoint calibration will throw position errors.

1. 1

   Depressurize the System

   Ensure the tractor is off and hydraulic pressure is fully relieved from the rear remotes.

2. 2

   Isolate the Fault

   If your specific valve block allows the electronic actuator/potentiometer cap to be removed separately, you can swap the electronic head from Remote #2 to Remote #3. If the fault code moves to Remote #3 (e.g., Code 4128/4131), the sensor cap is the culprit. If the code stays at #2, the mechanical spool inside the valve is sticking or damaged.

3. 3

   Replace the Component

   Replace the faulty spool position potentiometer. On many Case IH models, the sensor is integrated into the valve slice, requiring the replacement of the entire EHR Hydraulic Valve Section.

4. 4

   Reconfigure and Calibrate

   After installing the new valve section or sensor, use the Electronic Service Tool (EST) or the in-cab monitor to download the correct software configuration (if a new module was installed) and perform the EHR valve calibration procedure.

5. 5

   Clear and Test

   Clear the error codes and test the #2 remote for normal operation.