Case IH 4191 – Central Controller (XCM, ACM, or TCU): EHR 2 Offline Err / Rear remote No. 2 - no communication

The tractor's central controller has lost CAN bus communication with the Electro-Hydraulic Remote (EHR) valve number 2. This means the CAN messages received from or sent to EHR valve 2 are corrupted, missing, or the valve is completely offline.

• Magnum
• Magnum Series (235-340 Series 4)
• Steiger Series (350-600 HP)
• Puma Series
• Maxxum / MXM Series (MXM120, MXM130, MXM140, MXM155, MXM175, MXM190)

1. 1

   Test the wiring harness from the cab controls to the central controller, and from the controller to the rear remote valves for open circuits, short circuits, or chafed wires.

2. 2

   Verify the power supply to Valve 2 to ensure it is not experiencing under-voltage or over-voltage conditions.

3. 3

   Use the tractor's onboard diagnostics (e.g., the 'HH menu' on MXM models) to verify that the EHR control unit levers, float switches, and active switches are functioning.

4. 4

   Connect a diagnostic tool to monitor live CAN bus data and confirm if the controller is receiving corrupted messages from the valve.

1. 1

   Inspect Connections

   Disconnect the electrical harness at EHR valve 2 and the central controller. Clean the pins and check for corrosion or pushed-back pins. Reconnect and clear the code to see if communication returns.

2. 2

   Repair Harness

   If continuity tests reveal a break or short in the CAN lines or power supply wires between the XCM/ACM and the valve, repair or replace the affected harness section.

3. 3

   Replace the Valve

   If the wiring and voltage are correct but the valve remains offline, the internal output stage or transducer of EHR valve 2 has likely failed. Remove the faulty hydraulic remote valve assembly and install a replacement.

4. 4

   Calibrate the New Valve

   After replacing the valve, perform a hydraulic calibration (e.g., HH menu > H1). Hitch and remote calibrations must be attempted with the engine running, as an engine speed signal is required.

5. 5

   Software Update

   If the new valve still fails to communicate or calibrate, contact a dealer to verify if the central controller requires a software re-flash or update.