Case IH 1991-08 - UCM – UCM: Rear pilot head #7 failed to initialize

The electronic pilot head (the solenoid/actuator assembly that controls the hydraulic flow for a specific remote valve) on the #7 rear remote has failed to communicate or initialize on the tractor's CAN bus network. A shorted or internally failed pilot head can disrupt the entire CAN bus communication line, which often causes the other remote valves to go offline or stop functioning as well.

• MAGNUM AFS Connect
• Magnum 210
• Magnum 280
• Steiger 350
• Steiger 400
• Steiger 450
• Steiger 500
• Steiger 580
• Quadtrac 370
• Quadtrac 420
• Quadtrac 450
• Quadtrac 470
• Quadtrac 500
• Puma 185
• Puma 200
• Puma 220
• Puma 240 CVT
• Optum 270
• Optum 300

1. 1

   Locate the #7 rear remote pilot head.

2. 2

   Unplug the electrical connector to the #7 pilot head.

3. 3

   Check the tractor's monitor to see if the rest of the remote valves come back online. Unplugging the defective unit will often restore communication to the remaining valves, confirming that the #7 pilot head is the source of the network failure.

1. 1

   Disconnect the electrical harness from the faulty #7 pilot head to isolate it from the CAN bus.

   Disconnect the electrical harness from the faulty #7 pilot head to isolate it from the CAN bus.

2. 2

   Unbolt and remove the defective pilot head valve assembly from the rear remote valve stack.

   Unbolt and remove the defective pilot head valve assembly from the rear remote valve stack.

3. 3

   Install the replacement pilot head valve assembly.

   Install the replacement pilot head valve assembly.

4. 4

   Reconnect the electrical harness.

   Reconnect the electrical harness.

5. 5

   Perform a hydraulic valve calibration via the tractor's display/diagnostic system so the UCM can properly initialize and learn the new pilot head.

   Perform a hydraulic valve calibration via the tractor's display/diagnostic system so the UCM can properly initialize and learn the new pilot head.