John Deere 444.03 – Front Console Control Unit (FCC) / Dash Module: Control Software, Supply Voltage (BAT) Too High

The unswitched battery voltage supplied to the module has exceeded the maximum safe operating threshold (typically over 15.5 volts). This is usually caused by an overcharging alternator, a short to a higher voltage source in the wiring harness, or an internal failure within the module itself.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6090MC
• 6100MC
• 6110MC
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 7210R
• 7230R
• 7250R
• 7270R
• 7290R
• 8245R through 8400R
• 8320RT
• 8345RT
• 8370RT
• 9360R
• 9410R
• 9460R
• 9510R
• 9560R
• 9470RT
• 9520RT
• 9570RT

1. 1

   Test the battery voltage with the engine off (should read approximately 12.6 volts).

2. 2

   Verify charging system performance by starting the engine and testing voltage at the battery terminals (normal is 13.5V - 14.5V; over 15.5V indicates overcharging).

3. 3

   Inspect the unswitched battery supply wiring (BAT) leading to the Front Console Control Unit (FCC) for any shorts to a higher voltage source.

4. 4

   Ensure the ground connections for the FCC module and the battery are clean, secure, and free from corrosion.

1. 1

   Test the Alternator

   Connect a multimeter to the battery terminals and run the engine at a fast idle. If the multimeter reads over 15.5 volts, the voltage regulator has failed. Replace the alternator (or voltage regulator, if serviced separately).

2. 2

   Inspect the Harness

   If the charging system voltage is normal (under 15V), disconnect the wiring harness from the FCC (Dash Module). Measure the voltage at the unswitched power supply pins on the connector.

3. 3

   Repair Wiring

   If the voltage at the pins is abnormally high compared to the battery, trace the harness back to find and repair the short to power.

4. 4

   Replace the Module

   If the charging system is functioning correctly and the wiring harness delivers normal battery voltage to the connector, but the code remains active, the FCC module has an internal fault. Replace the Front Console Control Unit.

5. 5

   Calibrate and Clear

   Install the new FCC module. Note that a new module will require configuration and calibration (EOL data programming) using John Deere Service ADVISOR. Clear the diagnostic trouble codes and test the machine to verify the repair.