Case IH R37 – XCM: No Communication Between The EHR Valve 3 And The Central Controller (XCM)

The central controller has lost CAN bus communication with the Electronic Hitch Regulation (EHR) Valve 3 (3rd remote valve). Because of this communication loss, the controller can no longer send hydraulic flow commands to the valve or receive spool position status updates from it.

• MXM
• MXM Series
• Maxxum Series
• Puma Series
• Magnum Series

1. 1

   Check for accompanying CAN bus codes (e.g., R43, R47, R53, R57) to rule out a main CAN bus or XCM failure rather than a single valve issue

2. 2

   Visually inspect the wiring harness and connectors between EHR Valve 3 and the XCM for chafed wires, pinched harnesses, or corrosion inside the connector pins

3. 3

   Verify that EHR Valve 3 is receiving proper 12V power and a solid ground, as a dead module will not communicate

4. 4

   Use a multimeter to check the continuity and resistance of the CAN High and CAN Low wires between the XCM and the EHR Valve 3 connector

1. 1

   Disconnect Power

   Turn off the key switch and disconnect the tractor's battery to prevent electrical spikes during repair.

2. 2

   Clean and Re-seat Connectors

   Disconnect the electrical plug at EHR Valve 3. Clean the contacts with electronic contact cleaner, apply dielectric grease, and firmly reconnect it. Reconnect the battery and test. If the code clears, it was a poor connection.

3. 3

   Repair Wiring

   If the continuity test revealed an open or shorted CAN wire, repair the wiring harness using OEM-approved splicing methods or replace the affected harness section.

4. 4

   Replace the EHR Valve/Module

   If power, ground, and CAN wiring are all verified as good, the electronic module on EHR Valve 3 has failed internally. Replace the EHR valve assembly.

5. 5

   Perform Calibration

   If the EHR valve or the XCM is replaced, you must perform a system calibration. Enter the tractor's 'H-Menu' (specifically the HL menu for EHR valves) using the Electronic Service Tool (EST) or the tractor's diagnostic test switch to configure and calibrate the new valve to the XCM.