Case IH 1919-19 - UCM – UCM: Rear pilot head #1 reporting communication fault with vehicle controller

The tractor's main controller has lost CAN bus communication with the electronic actuator (the "pilot head") mounted on the #1 rear electro-hydraulic remote (EHR) valve slice.

• MAGNUM AFS Connect
• Steiger AFS Connect

1. 1

   Inspect the wiring harness and the electrical connector at the #1 rear remote valve pilot head for corrosion, moisture intrusion, or pushed/bent pins.

2. 2

   Verify that the pilot head is receiving steady 12V power and has a solid ground at the connector.

3. 3

   Check the CAN High and CAN Low lines at the connector for continuity back to the UCM and verify proper CAN bus terminating resistance (typically 60 ohms across the circuit).

4. 4

   Swap the #1 pilot head with the #2 pilot head. If the fault code changes to indicate a communication loss with the #2 remote, the pilot head itself has failed internally. If the fault remains on the #1 circuit, the issue is in the tractor's wiring harness or the UCM.

1. 1

   Turn off the tractor and engage the master battery disconnect switch to prevent electrical shorts.

   Turn off the tractor and engage the master battery disconnect switch to prevent electrical shorts.

2. 2

   Thoroughly clean the area around the #1 rear remote valve to prevent dirt from entering the hydraulic system.

   Thoroughly clean the area around the #1 rear remote valve to prevent dirt from entering the hydraulic system.

3. 3

   Unplug the electrical connector from the faulty pilot head.

   Unplug the electrical connector from the faulty pilot head.

4. 4

   Remove the retaining screws (typically hex or Torx) securing the pilot head to the hydraulic valve slice.

   Remove the retaining screws (typically hex or Torx) securing the pilot head to the hydraulic valve slice.

5. 5

   Carefully pull the pilot head straight back.

   Carefully pull the pilot head straight back. Note: Be careful not to lose any internal adapter plates, check balls, or springs that may be seated between the head and the valve body.

6. 6

   Install the new pilot head assembly and torque the retaining screws to OEM specification.

   Install the new pilot head assembly and torque the retaining screws to OEM specification.

7. 7

   Reconnect the electrical harness.

   Reconnect the electrical harness.

8. 8

   Power on the tractor and perform the EHR Valve Calibration Procedure.

   Power on the tractor. You must use the AFS Pro display (via the HH menu) or the Case IH EST (Electronic Service Tool) software to re-address the new valve and perform the EHR Valve Calibration Procedure so the UCM recognizes the new pilot head's limits.