Case IH 2307-03 - UCM – UCM: Front pilot head #3 reporting supply voltage high

The microprocessor inside the front hydraulic remote valve #3 pilot head is detecting and reporting an abnormally high electrical supply voltage.

• MAGNUM AFS Connect
• Steiger AFS Connect

1. 1

   Verify the tractor's overall system voltage and check for other UCM power supply codes (e.g., 1901) to rule out an overcharging alternator.

2. 2

   Inspect the wiring harness and connector at the pilot head for water ingress, corrosion, or a short-to-power condition on the supply pins.

3. 3

   Ensure the CAN bus connections (VB2) are intact so the pilot head can communicate properly with the UCM.

4. 4

   Verify through the tractor's display that the EHR valve is correctly addressed and numbered as valve #3 on the network.

1. 1

   Power Down

   Turn off the tractor, lower all hydraulic implements to the ground to relieve pressure, and disconnect the battery.

2. 2

   Locate the Valve

   Locate the front hydraulic remote valve stack and identify valve #3.

3. 3

   Test the Circuit

   Disconnect the harness from the pilot head on valve #3. Using a multimeter, test the supply voltage pins on the tractor-side harness with the key ON. If the voltage is within normal 12V operating range (approx. 12.5V - 14.2V), the issue is internal to the pilot head's microprocessor/sensor.

4. 4

   Replace the Pilot Head

   If the harness voltage is normal but the fault persists, the pilot head itself has failed. Remove the retaining hardware securing the electronic pilot head to the mechanical valve body and install a new pilot head.

5. 5

   Calibrate the Valve

   Navigate to the EHR Calibration menu on the tractor's display (or use the electronic service tool). Select the specific remote valve (#3) and initiate the calibration sequence. The display will indicate when the calibration is successful. (Note: A special diagnostic test harness/tool, OEM part number 380001903, is sometimes required to be plugged into the diagnostic couplers during this procedure depending on the exact hydraulic pump configuration).