John Deere 444.04 – HCC (Hitch Control Center): Switched Supply Voltage Low

The supply voltage to the module has dropped below 9.0 volts, indicating an electrical supply issue where the module is not receiving enough power to operate its software and control circuits reliably.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 5090M
• 5100M
• 5100MH
• 5100ML
• 5115M
• 5115ML
• 6090MC
• 6090RC
• 6100MC
• 6100RC
• 6110MC
• 6110RC
• 6145R
• 8245R
• 8400R
• 4555
• 4755
• 4955
• 4560
• 4760
• 4960
• 8560
• 8760
• 8960

1. 1

   Cycle the key switch or tractor power to check if the code goes away, which may indicate an intermittent voltage drop.

2. 2

   Perform a load test by reducing the electrical load (turn off lights, A/C, etc.) or increasing the engine RPM to see if the system recovers, indicating a failing alternator or overloaded charging system.

3. 3

   Test the battery voltage and alternator output, as a failing battery or bad alternator is the most common cause of a sub-9V drop.

4. 4

   Power down the tractor and check the specific fuses and relays supplying the Hitch Control Module.

5. 5

   Inspect the wiring harness leading to the HCC (specifically the switched power pins, often noted as Pin J4) for corrosion, loose grounds, or wire chafing.

1. 1

   Verify Voltage at the Module

   Disconnect the harness from the HCC. Use a multimeter to measure the voltage at the switched power supply pin while the key is in the ON position. It should read standard battery voltage (approx. 12V+).

2. 2

   Repair Wiring/Supply

   If the voltage at the connector is below 9V, trace the circuit back to the fuse panel and battery. Repair any damaged wires, clean corroded ground terminals, and replace blown fuses or faulty ignition relays.

3. 3

   Clean Connections

   If the voltage is correct at the harness but the code persists, clean the HCC connector pins with electrical contact cleaner and apply dielectric grease to ensure a solid connection.

4. 4

   Replace the HCC

   If the charging system is healthy, the wiring is intact, and a full 12V is reaching the module but the HCC still registers an internal low voltage fault (000444.04), the module's internal power supply circuit has failed. The HCC must be replaced.

5. 5

   Recalibrate

   If a new HCC is installed, you must perform a Hitch Control Unit (HCU) Calibration using John Deere Service ADVISOR or the tractor's CommandCenter display, as a new module will throw a Not Calibrated code (HCC 000630.13) upon installation.