Case IH R12 – XCM (Central Controller / Electronic Hydraulic Remote Controller): EHR Control Unit 1 Active Switch Error

The system has detected an electrical fault, short, open circuit, or implausible signal coming from the "active switch" (the neutral/raise/lower activation switch) on the Electronic Hydraulic Remote (EHR) valve 1 control lever.

• MXM
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190

1. 1

   Enter the tractor's built-in diagnostic H-Menu (H5) to test switch inputs and actuate the Remote 1 lever to see if the XCM registers the signal.

2. 2

   Remove the armrest/console cover and visually inspect the wiring harness and connectors between the EHR Remote 1 lever and the XCM controller for pinched wires, corrosion, or backed-out pins.

3. 3

   With the key switch OFF, disconnect the Remote 1 lever connector and test the switch for proper continuity/resistance when the lever is moved out of the neutral position.

4. 4

   Ensure the lever is receiving its 5V reference signal and has a solid ground connection.

1. 1

   Power Down

   Park the tractor, apply the parking brake, turn the key switch to the OFF position, and disconnect the battery if repairing the wiring harness.

2. 2

   Access the Controls

   Remove the right-hand armrest pod covers to expose the EHR remote levers and their sub-harnesses.

3. 3

   Disconnect the Lever

   Unplug the electrical connector specifically routed to the Remote 1 lever (often color-coded blue for Remote 1).

4. 4

   Repair or Replace

   If wiring is damaged: Repair the affected wires using a CNH harness repair kit, ensuring correct pin seating. If the switch/lever failed the H5 or multimeter test: Remove the mounting screws holding the Remote 1 lever assembly in the console and install a new or remanufactured lever assembly.

5. 5

   Reassembly

   Reconnect the electrical connector and reinstall the armrest pod covers.

6. 6

   Recalibration

   Whenever an EHR lever or controller is replaced, or a mechanical repair is effected, the system must be recalibrated. Turn the key ON, enter the H1 menu in the tractor's diagnostic display, and follow the on-screen prompts to calibrate the EHR valves.