New Holland EHR 4301 – Armrest Controller Module (ACM) or Central Controller (XCM) / Tractor Controller Unit (TCU): Rear Remote No.6 - No EHR Control Messages

CAN bus communication failure. The tractor's main controller has lost communication with the internal microprocessor located inside the Electronic Hydraulic Remote (EHR) valve section #6.

• T6 Series
• T7 Series
• T8 Series
• T9 Series
• Magnum (Series 4)
• Puma
• Steiger

1. 1

   Inspect the electrical connector at Rear Remote Valve #6 (C280 or equivalent) for moisture, corrosion, or pushed-out pins.

2. 2

   Verify that the valve is receiving a solid 12V supply and has a clean ground connection.

3. 3

   Perform a CAN Bus Resistance Test: Disconnect the EHR valve connector and measure the resistance across the CAN High and CAN Low pins (typically Yellow and Green wires). Approximately 60 Ohms means wiring is intact; 120 Ohms indicates an open circuit or missing resistor; <5 Ohms indicates a short circuit.

4. 4

   Perform a Swap Test: Swap the electrical connector of Remote #6 with an adjacent, known-good remote (e.g., Remote #5). If the fault code changes to the other remote, the EHR valve itself has an internal module failure. If the code remains EHR 4301, the issue is in the tractor's wiring harness.

1. 1

   Depressurize the System

   Turn off the tractor, lower all implements, and relieve hydraulic pressure by cycling the remote levers/buttons with the key on (engine off).

2. 2

   Disconnect Battery

   Disconnect the negative battery cable to protect the CAN bus network.

3. 3

   Clean the Area

   Thoroughly clean the rear remote valve stack to prevent dirt from entering the hydraulic system during disassembly.

4. 4

   Remove Connections

   Disconnect the hydraulic lines and the electrical connector from Remote Valve #6.

5. 5

   Disassemble the Valve Stack

   Unbolt the tie-rods/mounting bolts that hold the remote valve stack together. Carefully separate the slices.

6. 6

   Replace the Valve

   Remove the faulty EHR valve section. Install the new valve section, ensuring that all new O-rings are properly seated between the valve slices to prevent internal/external leaks.

7. 7

   Reassembly

   Re-torque the valve stack tie-rods to the exact OEM specifications for your specific tractor model. Reconnect the hydraulic lines and the electrical connector.

8. 8

   Calibration

   Reconnect the battery. Use the tractor's in-cab display (or a diagnostic tool like CNH EST/Jaltest) to clear the fault codes. You must perform a hydraulic valve calibration procedure so the central controller can learn the spool travel limits of the new valve.