Case IH 4105 – EHR (Electronic Hydraulic Remote) controller: Rear remote no. 1 - over voltage

The control module is receiving a voltage signal from the Rear Remote #1 circuit that exceeds the maximum allowable threshold. This is typically caused by a short to power in the signal wire, an open ground circuit on the sensor, or an internal failure of the spool position potentiometer.

• Magnum
• Maxxum
• Steiger T4B
• MAXXUM T4E
• VESTRUM CVX
• Puma
• Steiger
• Farmall

1. 1

   Check valve LED flash codes visible through the plastic part of the valve casing to confirm localized valve error.

2. 2

   Perform a swap test by swapping the electrical connector from Rear Remote No. 1 with Rear Remote No. 2 to isolate the fault to the valve or the harness.

3. 3

   Check the wiring harness at the remote valve using a multimeter to test the 5V reference, ground, and signal wires for a short to 12V or a broken ground.

4. 4

   Monitor live data in the diagnostic menu or EST to see if potentiometer readings are maxed out (e.g., >4840).

1. 1

   Safety First

   Lower all implements to the ground, turn off the engine, disconnect the batteries, and block the machine to prevent movement.

2. 2

   Clean the Area

   Thoroughly clean the rear remote valve stack to prevent dirt from entering the hydraulic system when removing components.

3. 3

   Repair Wiring

   If the diagnostic checks revealed a short to power or an open ground in the harness, repair the damaged wire or replace the connector pigtail.

4. 4

   Replace the Potentiometer / Valve

   If the harness tests good, the potentiometer on the EHR valve has failed. Unbolt and replace the position potentiometer independently on older models, or replace the electronic control head/entire remote valve assembly on modern Bosch Rexroth EHR valves.

5. 5

   Reassemble and Power Up

   Reconnect the EHR harness and reconnect the batteries.

6. 6

   Calibrate the EHR System

   Perform the EHR valve calibration procedure using the tractor's display monitor or the CNH Electronic Service Tool (EST) so the controller can learn the new neutral, extend, and retract voltage parameters.