Case IH 1991-04 - UCM – UCM: Rear pilot head #7 reporting supply voltage low

The control module has detected that the electrical supply voltage reaching the actuator (pilot head/solenoid) for the #7 rear auxiliary remote valve is below the normal operating range. This typically disables the affected remote valve to prevent erratic hydraulic operation.

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

1. 1

   Verify battery and charging system voltage (must be at least 12.6V resting and 13.5V+ when running).

2. 2

   Inspect the wiring harness running from the UCM to the rear remote valve stack for chafed wires, pinched harnesses, or damage near the exhaust/frame areas.

3. 3

   Disconnect the plug at the #7 rear remote pilot head and check for water ingress, dirt, or corroded pins.

4. 4

   Perform a component swap test by swapping the electrical connector from the #7 pilot head with an adjacent known-good remote (e.g., #6). If the fault code changes to the new remote number, the pilot head is faulty. If it remains on #7, the issue is in the wiring or UCM.

1. 1

   Clean and re-seat connections

   With the tractor turned off, disconnect the #7 pilot head connector and the corresponding UCM connector (Connector 92). Clean both with electrical contact cleaner and apply dielectric grease. Reconnect and cycle the key to see if the code clears.

2. 2

   Repair wiring harness

   If a voltage drop is confirmed via a multimeter at the pilot head connector, trace the power supply circuit back to the UCM. Repair any broken or corroded wires in the harness.

3. 3

   Replace the pilot head

   If the wiring tests good and the swap test points to a failed actuator, remove the retaining hardware securing the pilot head to the #7 hydraulic valve section and install a new pilot head assembly.

4. 4

   Reassign and calibrate valves

   After replacing a pilot head, reassign the pilot heads using the tractor's display monitor (via the 'H menu' or AFS Pro 1200 display) or by using the Case IH Electronic Service Tool (EST) so the UCM recognizes the new valve actuator.