John Deere 000923.01 – ATC: M07/M10 Fan Motor, Power Supply Fault at Power Module (HF) PC6

This code indicates a severe voltage drop or power supply failure to the cab HVAC blower motors. Specifically, the PC6 Power Module measures less than 3 volts at the supply voltage for one or both fan motor outputs (lead 0752 and/or lead 0762). The diagnostic trouble code is generated when the fan motors (M07 and M10) are switched on, but the module detects insufficient power to drive them. This fault code is logged against the ATC (Automatic Temperature Control) unit, specifically pointing to a hardware failure or wiring issue at the PC6 Power Module (HF), which controls cab power distribution.

• 6230
• 6330
• 6430
• 7130
• 7230
• 7330
• 7430
• 7530

1. 1

   Verify all cab and HVAC-related fuses (e.g., F06/01, F06/02) to ensure the PC6 module is receiving proper input voltage.

2. 2

   Access the PC6 Power Module and inspect the wiring harness for leads 0752 and 0762. Look for pinched wires, corrosion at the connectors, or shorts to ground.

3. 3

   Back-probe the PC6 module outputs for the fan motors. Command the fans on and verify if the voltage drops below 3V.

4. 4

   Disconnect the M07 and M10 fan motors to isolate the components. If the voltage at the PC6 module returns to normal (12V) when the motors are unplugged (shorted motor cause), one or both of the fan motors are internally shorted. If the voltage remains below 3V with the motors unplugged (wiring or module cause), the wiring harness or the PC6 module itself is faulty.

1. 1

   Disconnect power

   Turn off the tractor and disconnect the negative battery cable to prevent electrical spikes.

2. 2

   Access the components

   Remove the cab roof panel or headliner to access the HVAC blower motors (M07/M10) and the PC6 Power Module.

3. 3

   Repair wiring

   If diagnostic tests revealed a short or break in leads 0752 or 0762 (wiring cause), repair the damaged section of the harness and replace the connector pins if they show signs of heat damage or corrosion.

4. 4

   Replace blower motor(s)

   If a fan motor was found to be shorted (shorted motor cause), unbolt the faulty blower motor assembly from the HVAC housing. Install the new blower motor and plug in the 2-wire connector.

5. 5

   Replace PC6 module

   If the motors and wiring tested fine but the module fails to output voltage (module cause), unbolt the PC6 Power Module, disconnect its harness, and install a replacement unit.

6. 6

   Reassembly and testing

   Reconnect the battery. Turn the key to the ON position and clear the ATC fault codes. Turn on the ATC system and test the fan motors across all speed settings to verify the repair. Reinstall the cab roof/headliner.