Case IH 1979-12 - UCM – UCM: Rear pilot head #6 reporting internal controller fault

The internal circuitry of the pilot head controlling the #6 rear remote has failed, causing the remote valve to lock up or go offline.

• MAGNUM AFS Connect
• Steiger / Quadtrac Series (e.g., 350, 400, 450, 470, 500, 540, 580, 600, 620)
• Magnum Series (e.g., 210, 280, 290)
• Puma Series (e.g., 170, 185, 200, 220, 240)
• Optum Series (e.g., 270, 300)

1. 1

   Verify the code using the Case IH Electronic Service Tool (EST) to confirm 1979-12 is active and isolating the #6 remote.

2. 2

   Inspect the wiring harness and 4-pin connector at the #6 pilot head for dirt, moisture, or damaged pins, which can mimic an internal fault.

3. 3

   Temporarily swap the #6 pilot head with a known good pilot head from an adjacent remote (e.g., #5) to see if the fault code follows the component.

1. 1

   Preparation

   Turn off the tractor, relieve all hydraulic system pressure, and thoroughly clean the area around the #6 remote valve to prevent dirt from entering the hydraulic system.

2. 2

   Removal

   Disconnect the electrical harness from the #6 pilot head. Remove the hex socket screws (typically M5 x 20mm) securing the pilot head to the remote valve slice.

3. 3

   O-Ring Replacement

   Remove the faulty pilot head. Remove and discard the old O-rings at the slice/pilot head interface. Install new O-rings.

4. 4

   Installation

   Mount the new pilot head assembly onto the valve body and torque the mounting screws to factory specifications. Reconnect the electrical harness.

5. 5

   Reassign Valve Addresses

   Connect the Case IH EST and reassign the valve addresses so the UCM recognizes the new pilot head and knows which cab lever controls it.

6. 6

   Calibration

   Perform the EHR calibration procedure using the EST. This tunes the valve to ensure proper proportional flow, especially important if the remote is used for constant flow functions like running a vacuum fan motor.

7. 7

   Clear Codes

   Clear the 1979-12 fault code from the UCM memory and test the remote for proper operation.