Case IH 1955-13 - UCM – UCM: Rear pilot head #4 internal controller failure or spool valve position sensor not calibrated

The position transducer inside the electro-hydraulic remote (EHR) actuator (the pilot head) cannot verify that the spool is in the correct neutral position upon activation, or it has lost its learned calibration limits. This prevents the tractor from safely operating the #4 rear remote valve, as the system cannot accurately determine the physical position of the hydraulic spool.

• MAGNUM AFS Connect
• Case IH Magnum AFS Connect
• Case IH Steiger / Quadtrac AFS Connect

1. 1

   Check for related voltage codes on the #4 remote (e.g., 1955-09 for low supply voltage, 1955-04 for high supply voltage, or 1955-12 for spool not in neutral). If present, the issue is likely in the wiring harness rather than the valve.

2. 2

   Cycle the tractor power and check if the UCM registers code 1955-11 (unexpected reset of rear pilot head #4), which can indicate an intermittent electrical short.

3. 3

   Inspect the #4 rear remote valve for physical binding, dirt, or debris in the coupler that might mechanically prevent the spool from returning to neutral.

4. 4

   Swap the electronic pilot head (actuator) from remote #4 with an adjacent remote (e.g., #3). If the fault code follows the pilot head, the internal position sensor has failed. If the code stays on #4, the issue is in the wiring harness or the UCM.

1. 1

   Harness & Connector Maintenance

   Park the tractor on a level surface, lower all implements, turn off the engine, and relieve all hydraulic pressure. Disconnect the electrical connector at the #4 rear remote pilot head. Inspect the pins for corrosion, moisture ingress, or pushed-out pins. Clean the contacts with electrical contact cleaner and apply dielectric grease before reconnecting.

2. 2

   Spool Valve Calibration

   Ensure the transmission/hydraulic oil is warmed up to normal operating temperature. Turn the ignition ON and access the AFS Pro 1200 display. Navigate to the Vehicle Settings icon -> Menu Diagnostics -> Vehicle Diagnostics. Select the Calibration Wizard and choose the Remote Valve / EHR Calibration procedure. Follow the on-screen prompts. The system will actuate the spool to learn the physical limits of the valve.

3. 3

   Replace the Pilot Head

   If the calibration fails or the 1955-13 code immediately returns, the internal position transducer is permanently faulty. Remove the retaining screws holding the electronic pilot head to the #4 hydraulic spool valve body. Carefully remove the faulty pilot head, ensuring no dirt enters the hydraulic valve body. Install the new pilot head, ensuring the mechanical linkage aligns perfectly with the spool. Torque the retaining screws to OEM specification and reconnect the electrical harness. Crucial: You must repeat the EHR spool valve calibration via the AFS Pro 1200 display so the UCM can learn the new sensor's values.