Case IH 1919-13 - UCM – UCM (Universal Control Module): Rear pilot head #1 reporting that spool valve position sensor is not calibrated

This fault indicates that the electronic controller does not know the neutral, extend, or retract limits of the hydraulic spool valve. The spool valve position sensor provides accurate feedback to the control unit for precise operation of hydraulic functions. When it is "not calibrated," the system cannot safely or accurately actuate the remote valve, and the function is typically disabled until a calibration is successfully performed.

• MAGNUM AFS Connect
• Magnum Series Tractors (e.g., MX Magnum, Magnum 180, 235–340)
• Steiger Series Tractors
• Puma and Maxxum Series Tractors
• Axial-Flow Combines (e.g., 7240/8240/9240 Series)

1. 1

   Check UCM Power Supply: Verify that the UCM is receiving proper voltage. Look for accompanying UCM power supply faults (e.g., 1901 UCM Supply Voltage High, 1902 UCM Supply Voltage Low, or 1905 5VREF1 Sensor Supply Voltage Out of Range) which can cause sensors to drop offline.

2. 2

   Inspect Wiring and Connectors: Inspect the wiring harness from the UCM to the rear remote valve. Check the connector pins at the UCM and the spool valve position sensor for water ingress, dirt, or corrosion.

3. 3

   Check for Mechanical Binding: Ensure the spool valve core moves freely within the bore and is not mechanically stuck, which can prevent the sensor from reading the full range of motion during calibration.

1. 1

   Clean and Reconnect

   If dirt or moisture is found in the UCM or remote valve connectors, clean the pins with electrical contact cleaner, apply dielectric grease, and reconnect.

2. 2

   Perform Spool Valve Calibration

   If a spool valve or sensor has lost its memory or was recently replaced, it must be assigned its positional limits. Connect a premium diagnostic tool (such as the Case IH EST or Jaltest AGV) or navigate to the calibration menu on the tractor's AFS Pro display terminal. Initiate the "Spool Valve Calibration" or "Rear Remote Calibration" procedure. Follow the on-screen prompts to cycle the valve through its full extend, retract, and neutral positions.

3. 3

   Replace the Sensor/Valve

   If the calibration fails repeatedly, or if the sensor is internally shorted/open, replace the spool position sensor or the entire remote valve section.

4. 4

   Recalibrate

   After installing the new part, you must perform the spool valve calibration procedure again to marry the new sensor to the UCM.