New Holland TRANS 2913 – TRANS: 12VH voltage supply is low. (possible blown fuse*)

The voltage on the 12VH power supply rail has dropped below the minimum operational threshold (typically below 8 volts). This circuit provides critical B+ power to the controller for transmission and implement functions. When this voltage drops, the system will often default to a safe state, which can cause the transmission to drop into Park or lock up unexpectedly.

• New Holland T8.xxx Series (e.g., T8.390, T8.410)
• New Holland T6 and T7 Series
• Various New Holland construction equipment (skid steers and loaders)

1. 1

   Check the 12VH / UCM B+ circuit fuse located in the main fuse panel

2. 2

   Inspect the Forward/Neutral/Reverse/Park (FNRP) switch and park brake solenoid for shorts, corrosion, or damage

3. 3

   Test the power relay supplying the 12VH circuit for proper continuity across the relay pins (e.g., pin 30 to pin 87) when energized

4. 4

   Inspect the wiring harness between the fuse block and the transmission controller for a short to ground or an open circuit

1. 1

   Power Down

   Turn off the tractor, remove the key, and disconnect the battery ground cable to ensure safety while working on the electrical system.

2. 2

   Access the Fuse Panel

   Remove the cover or rubber liner to access the main fuse and relay panel.

3. 3

   Locate the 12VH Fuse

   Consult the fuse diagram for your specific model to find the 12VH UCM/VCM B+ fuse (often labeled F-015, F-026, or F-070 depending on the cab layout). It is typically a 20-amp mini fuse.

4. 4

   Replace the Fuse

   If the fuse is blown, replace it with a new 20A mini fuse.

5. 5

   Trace for Shorts

   If the new fuse blows immediately upon key-on, or if the original fuse was fine but voltage is still low at the module, use a multimeter to trace the 12VH wire. Look for chafed wires shorting against the tractor chassis, particularly near the transmission housing and park brake solenoid.

6. 6

   Repair Wiring/Components

   Repair any damaged wiring harness sections. If the park solenoid or FNRP switch is internally shorted, replace the faulty component.

7. 7

   Clear Codes

   Reconnect the battery. Turn the key on and use the CNH Electronic Service Tool (EST) to clear the TRANS 2913 fault code. Test drive the tractor to ensure the transmission shifts correctly and the code does not return.