John Deere 444.04 – VLC: Unswitched Supply Voltage Low

Triggers when the unswitched battery voltage supplied to the module drops below 9 volts. This condition typically indicates a failing battery, poor electrical connections, blown fuses, or a broader issue with the machine's charging system.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 7210R
• 7230R
• 7250R
• 7270R
• 7290R
• 8245R through 8400R
• 9470RT
• 9520RT
• 9570RT
• 770G
• 770GP
• 772G
• 772GP
• 872G
• 250D
• 300D
• 370E
• 410E
• 460E
• 700K
• 850K

1. 1

   Test the main battery to ensure it is holding a proper charge (12V+) and not dropping below 9V under load

2. 2

   Determine if the code is active or intermittent (intermittent points to a loose connection or chafed wire)

3. 3

   Check the main fuse panel for any blown fuses or faulty relays that supply unswitched power to the VLC

4. 4

   Inspect the unswitched power supply wiring (often noted as BAT at Terminal J4) leading to the VLC for corrosion, backed-out pins, or moisture

5. 5

   Ensure the ground strap/wire for the VLC is securely fastened to the chassis and free of rust or paint interference

1. 1

   Secure the Machine

   Turn off the engine, remove the key, and engage the parking brake.

2. 2

   Resolve Power Supply Issues

   If the battery failed the load test, replace it. If a fuse supplying the VLC is blown, replace it and check the circuit for shorts to ground.

3. 3

   Clean Connections

   Disconnect the main harness to the Vehicle Load Center (Rear Chassis Module). Spray the connectors with electrical contact cleaner. Re-seat the connector firmly, ensuring the locking tab engages.

4. 4

   Repair Wiring

   If you found chafed wires or corroded pins during the diagnostic phase, splice in new wire sections or replace the damaged connector pins using a John Deere approved wiring repair kit.

5. 5

   Module Replacement (If Necessary)

   If the battery, fuses, wiring, and grounds all test perfectly (showing 12V at the module connector), but the VLC still logs the 000444.04 code, the module's internal power circuitry has likely failed. Remove the mounting bolts, disconnect the harnesses, and install a new VLC.

6. 6

   Reprogramming

   A new VLC usually requires End-Of-Line (EOL) data calibration and programming via John Deere Service ADVISOR to function correctly with the machine's CAN bus network.

7. 7

   Clear Codes

   Turn the key on and use your diagnostic tool to clear the 000444.04 fault code. Verify it does not return.