Case IH 13010 - UCM – UCM: Supply voltage 12VA - voltage too low

The 12-volt power supply (specifically on the 12VA circuit) feeding the module has dropped below the minimum acceptable operating threshold.

• VESTRUM CVX
• Puma series
• Magnum series
• Steiger series
• Maxxum series

1. 1

   Verify that the battery is fully charged and that the alternator is outputting the correct voltage (low system voltage will trigger this code)

2. 2

   Use the ADIC display to enter the 'H9 - Voltmeter diagnostic' menu to monitor voltage circuits in real-time for sudden drops while operating or wiggling harnesses

3. 3

   Inspect the wiring harness relevant to the 12VA channel for chafed wires, open circuits, or shorts to ground

4. 4

   Check the specific fuses and relays that supply the 12VA circuit to the UCM

5. 5

   Use the 'H8' or 'HC' menu to clear stored error codes and determine if the code is a hard fault or an intermittent historical code

1. 1

   Disconnect Power

   Disconnect the battery negative cable before performing any electrical repairs to prevent short circuits.

2. 2

   Inspect the UCM Connectors

   Locate the UCM (often located behind the operator's seat on the right-hand rear pillar, depending on the cab layout). Disconnect the main harness and inspect the pins for corrosion, moisture, or pushed-back terminals.

3. 3

   Repair the Wiring

   If the H9 diagnostic or a multimeter continuity test reveals a break or high resistance in the 12VA supply wire, repair the damaged section of the harness using OEM-approved waterproof splices.

4. 4

   Replace Relays/Fuses

   If the supply relay is sticking or the fuse is blown/corroded, replace them.

5. 5

   Replace the UCM

   If the harness delivers a steady 12+ volts to the UCM under load, but the module still registers a "voltage too low" internal fault, the UCM has suffered an internal hardware failure and must be replaced.

6. 6

   Recalibrate

   After replacing the UCM, you must use the Electronic Service Tool (EST) or the ADIC menus to reconfigure the module and perform necessary calibrations (such as steering or transmission calibrations).