Case IH 1943-12 - UCM – UCM: Rear pilot head #3 spool not in neutral at activation

Rear pilot head #3 is reporting that the internal spool was not in the neutral position at the time of system activation/power-up. This typically points to a mechanical binding within the pilot head actuator, a failed internal position sensor, or a stuck remote lever.

• MAGNUM AFS Connect
• Case IH Magnum AFS Connect Series
• Case IH Steiger AFS Connect Series

1. 1

   Inspect the in-cab controls: Check the physical lever/joystick for the #3 remote valve in the cab to ensure it is not physically locked up or failing to return to neutral.

2. 2

   Check wiring and connections: Inspect the wiring harness and the electrical connector at the #3 rear pilot head for corrosion, backed-out pins, or wire chafing.

3. 3

   Component swap test: Swap the electronic pilot head from remote #3 with a known good remote (e.g., #2 or #4). If the fault follows the pilot head, the head is internally faulty. If it remains on #3, suspect a wiring or UCM issue.

4. 4

   Check for installation distortion: Ensure the valve stack is not under stress from unevenly tightened mounting bolts, which can cause the internal compensating spool to bind.

1. 1

   Locate valve

   Locate the #3 rear remote valve section on the rear hydraulic stack.

2. 2

   Clean area

   Thoroughly clean the area around the valve to prevent dirt from entering the hydraulic system.

3. 3

   Disconnect harness

   Disconnect the electrical harness connector from the #3 pilot head assembly.

4. 4

   Remove screws

   Remove the mounting screws (typically M5 x 20mm hex socket screws) securing the pilot head to the main valve body.

5. 5

   Remove pilot head

   Carefully pull the faulty pilot head assembly away from the valve section.

6. 6

   Inspect spool

   Inspect the main flow control spool inside the valve body to ensure it moves freely and is not scored. If the main spool is damaged, the entire valve section or spool may need replacement.

7. 7

   Lubricate O-rings

   Lubricate the O-rings on the new pilot head assembly with clean hydraulic oil.

8. 8

   Install pilot head

   Install the new pilot head onto the valve body.

9. 9

   Install screws

   Install the mounting screws and tighten them evenly to prevent distorting the housing and binding the spool.

10. 10

    Reconnect harness

    Reconnect the electrical harness.

11. 11

    Clear codes and calibrate

    Power on the tractor and use the Case IH Electronic Service Tool (EST) to clear the UCM fault codes and perform any necessary EHR valve calibrations.