Case IH R27 – Central Controller (XCM) / EHR Valve 2: No Communication Between The EHR Valve 2 And The Central Controller (XCM)

The CAN bus communication link between the tractor's Central Controller (XCM) and the electronic module mounted on the Electronic Hydraulic Remote (EHR) Valve #2 has been lost or interrupted.

• MXM
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• MX210
• MX230
• MX255
• MX285

1. 1

   Inspect the wiring harness and connectors running from the XCM to the EHR Valve 2 block at the rear of the tractor for pinched wires, rubbed insulation, or debris.

2. 2

   Verify that EHR Valve 2 is receiving proper 12V power and ground, as missing power prevents communication with the XCM.

3. 3

   Connect the CNH Electronic Service Tool (EST) to check the AUX controller status and perform a CAN bus diagnostic check to see if other valves are also dropping communication.

4. 4

   Check the EHR valve casing for LED flash codes (e.g., Flash Code 11 or 13 for CAN bus faults) to indicate internal software or CAN bus message faults.

1. 1

   Disconnect Power

   Turn off the key switch and disconnect the battery to prevent electrical spikes.

2. 2

   Clean and Inspect Connectors

   Disconnect the harness at EHR Valve 2 and at the XCM. Inspect the pins for corrosion, moisture, or pushed-back terminals. Clean the contacts with electrical contact cleaner and apply dielectric grease.

3. 3

   Test Harness Continuity

   Using a multimeter, test the continuity of the CAN High and CAN Low wires between the XCM connector and the EHR Valve 2 connector. Repair any open circuits or shorts to ground.

4. 4

   Component Swap (Optional for Diagnosis)

   If the wiring tests good, you can temporarily swap the electrical connections between EHR Valve 1 and EHR Valve 2 (if the harness allows). If the fault code changes from R27 to R17 (No communication with EHR Valve 1), the electronic head on the valve is faulty. If the code remains R27, the XCM or the specific wiring channel is faulty.

5. 5

   Replace Faulty Component

   Replace the failed EHR valve electronic head or the XCM controller.

6. 6

   Recalibration

   If the EHR valve or the XCM is replaced, the hydraulic system must be recalibrated. This can be done using the EST or via the tractor's onboard "H-Menu" (specifically the H1 menu for calibrations) to ensure the XCM recognizes the new valve's travel limits and flow rates.