Case IH 1931-09 - UCM – UCM: Rear pilot head #2 unexpected reset

This fault code indicates that the electronic actuator (known as the "pilot head") on the #2 rear remote hydraulic valve has rebooted or reset unexpectedly. An unexpected reset is typically caused by an intermittent drop in power or ground, a CAN bus communication failure, or an internal hardware failure within the pilot head itself. When this happens, the #2 remote valve will usually disable itself to prevent uncommanded hydraulic flow.

• MAGNUM AFS Connect
• Magnum series
• Steiger series
• Steiger AFS Connect
• Quadtrac series
• Quadtrac AFS Connect
• Puma series
• Optum series

1. 1

   Inspect the wiring harness and the connector plugging into the #2 rear remote pilot head for corrosion, moisture ingress, chafed wires, or pushed-out pins.

2. 2

   Verify that the pilot head is receiving a stable power supply and has a clean ground, as voltage drops under vibration can cause the module to reset.

3. 3

   Disconnect the remote valve connector and use a multimeter to check the resistance of the CAN wiring (typically between the blue and red wires, pins 2 and 3). It should read approximately 120 ohms.

4. 4

   Swap the #2 pilot head with an adjacent, known-good pilot head (such as #1 or #3). If the fault code follows the pilot head to the new location, the pilot head has an internal failure. If the fault code remains on #2, the issue is in the tractor's wiring harness.

1. 1

   Preparation

   Turn off the tractor, relieve all hydraulic pressure from the system, and thoroughly clean the area around the rear remote valves to prevent dirt from entering the hydraulic system.

2. 2

   Removal

   Disconnect the electrical harness from the faulty pilot head. Remove the hex socket screws securing the pilot head to the remote valve body (slice).

3. 3

   O-Rings

   Remove the old pilot head and discard the old O-rings located between the slice and the pilot head.

4. 4

   Installation

   Lubricate the new O-rings with clean hydraulic oil and install them. Mount the new pilot head assembly to the valve slice and torque the retaining screws to the manufacturer's specification. Reconnect the electrical harness.

5. 5

   Valve Reassignment

   Because a new pilot head with a new internal address was introduced to the CAN bus, you must reassign the valves. This teaches the UCM which physical valve corresponds to which in-cab lever. This is done via the tractor's display monitor or the Case IH Electronic Service Tool (EST).

6. 6

   Valve Calibration

   Perform an EHR valve calibration to tune the new pilot head for proper spool travel and hydraulic flow. This procedure often requires the use of a special pressure transducer (Case IH special tool #380001903) and a jumper harness (tool #84148258).