John Deere 000647.05 – ECU: Engine Fan Drive Circuit Fault

The Engine Control Unit (ECU) has detected an electrical fault within the engine's fan drive control system. Specifically, the 'Upper Fan Drive Output 1' circuit has been identified as being shorted or open, indicating high resistance in the electrical circuit for the solenoid that controls the hydraulic fan.

• 5085M
• 5100M
• 5115M
• 7630
• 7730
• 7830
• 7930
• 8230T
• 8330T
• 8430T
• 8R Series
• 8RT Series
• 9R Series
• 9RT Series
• 9RX Series

1. 1

   Check for related symptoms such as engine overheating, the cooling fan not engaging, or the fan running continuously (due to a fail-safe design)

2. 2

   Visually inspect the wiring harness and connectors leading to the fan drive solenoid coil on the fan drive piston housing for chafed wires, broken wires, loose connections, or corrosion

3. 3

   Perform basic electrical checks with a multimeter on the solenoid and its circuit to check for continuity (open circuits) and test for a short to ground

1. 1

   Disconnect battery

   Disconnect the battery before beginning any electrical repairs for safety.

2. 2

   Locate fan drive solenoid

   Identify the fan drive solenoid located on the fan drive piston housing.

3. 3

   Inspect and repair wiring

   Disconnect the electrical connector from the solenoid. Thoroughly clean the connector pins on both the harness and the solenoid. Check for a secure fit when reconnected. Repair or replace any damaged sections of the harness.

4. 4

   Test the solenoid

   If wiring is in good condition, apply power and ground directly to the solenoid to see if it actuates (clicks).

5. 5

   Replace solenoid or valve

   If the solenoid fails the actuation test, replace the fan drive solenoid or the complete fan drive control valve assembly.

6. 6

   Clear codes and verify

   Reconnect the battery, clear the fault code from the ECU, and operate the machine to ensure the cooling fan operates correctly and the fault does not return.