Case IH 13022 - UCM – UCM: Supply voltage 12VT1 - voltage too low

This fault code indicates that the control module is detecting that the voltage at the power input rail "12VT1" has dropped below the normal operational limit (typically below 9 Volts).

• VESTRUM CVX
• Puma
• Magnum
• Steiger
• Optum
• Maxxum
• Axial-Flow 7230
• Axial-Flow 8230
• Axial-Flow 9230
• Axial-Flow 7240
• Axial-Flow 8240
• Axial-Flow 9240
• SR Series
• SV Series
• TR Series
• TV Series
• SR175B
• TR270

1. 1

   Verify that the tractor's main battery and alternator voltage are normal (above 11.5V).

2. 2

   Inspect the cab main fuse box and check the specific fuse for the UCM 12VT1 power rail (often a 15A or 30A mini fuse designated as F-030, F-033, or F-305).

3. 3

   Check the UCM Power Relay (often designated as K-002 or K-007) in the fuse panel to ensure it is receiving the command to close and successfully passing voltage.

4. 4

   Inspect the wiring harness between the UCM Power Relay, the fuse, and the UCM for damaged wires, open circuits, or corroded splices (specifically Splice 118 and Splice 119).

1. 1

   Disconnect Power

   Turn off the key switch and disconnect the battery ground cable to prevent short circuits during inspection.

2. 2

   Inspect and Replace Fuse

   Access the main fuse/relay panel. Locate the fuse for the UCM 12VT1 circuit. If the fuse is blown, replace it with a new fuse of the exact same amperage.

3. 3

   Test/Replace the UCM Power Relay

   Remove the UCM Power Relay. Bench test the relay for continuity when energized, or swap it with a known good relay of the same type (like the horn or work light relay). If the relay is faulty, replace it.

4. 4

   Repair Wiring

   Reconnect the battery and turn the key ON. Probe the 12VT1 pin at the UCM connector. If the voltage is still below 9V, trace the wire back to the fuse panel. Repair any breaks, chafing, or corroded splices in the harness.

5. 5

   Clear Codes

   Reconnect the UCM. Use the Electronic Service Tool (EST) or the machine's onboard "H Menu" diagnostic display to clear the stored 13022 fault code.

6. 6

   Retest

   Cycle the key power and operate the machine to confirm the fault code does not return.