John Deere 444.04 – FCC: Supply Voltage (BAT) Too Low

The unswitched battery supply voltage to the module drops below a critical operating threshold (typically below 9 volts), compromising the module's ability to function correctly, log events, and maintain CAN bus system synchronization.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6125R
• 6090MC/RC
• 6100MC/RC
• 6110MC/RC
• 7200R
• 7215R
• 7230R
• 7260R
• 8225R
• 8245R
• 8320R

1. 1

   Verify the main vehicle batteries are fully charged and pass a load test, and ensure the alternator is outputting the correct voltage

2. 2

   Clear the code via the CommandCenter or Service ADVISOR and cycle the key switch to check for an intermittent wiring short or loose connection

3. 3

   Check the specific fuses and power relays that supply unswitched battery power to the Front Chassis Control unit

4. 4

   Inspect the front chassis/dash wiring harness for chafing, pinched wires, or corrosion, especially at the main FCC module connectors

5. 5

   Using a multimeter, perform a voltage drop test directly at the FCC module's unswitched power supply pins and ground pins while the system is under load (voltage below 9V with a good battery indicates high resistance in the harness)

1. 1

   Disconnect Power

   Always disconnect the negative battery cable before performing electrical repairs or unplugging modules.

2. 2

   Repair Wiring/Power Supply

   If the diagnostic checks revealed a blown fuse, corroded connector, or damaged wire in the power supply or ground circuits, repair or replace the affected wiring harness section. Clean all chassis ground points associated with the front harness.

3. 3

   Replace the Module

   If the wiring tests perfectly (showing full battery voltage and solid ground at the FCC connector) but the 000444.04 code remains active, the FCC module has suffered an internal hardware failure and must be replaced.

4. 4

   Installation

   Unbolt the faulty FCC module from its mounting bracket (usually located behind the dash/cowl area or on the front chassis firewall) and plug the harness into the new module.

5. 5

   Calibration/Programming

   Reconnect the battery. A new FCC module will likely require payload programming and End-of-Line (EOL) calibration using John Deere Service ADVISOR to sync it with the tractor's CAN bus network.

6. 6

   Clear Codes

   Clear the historical DTCs and test the machine's functions to verify the repair.