John Deere 647.06 – Engine Control Unit (ECU): Proportional Solenoid Valve Current Too High (Charge Air Cooler Hydraulic Motor) / Engine Fan Clutch Current Above Normal Or Grounded Circuit

The control software has detected that the electrical current output to the variable speed engine cooling fan solenoid (or charge air cooler hydraulic motor proportional solenoid valve) is too high. This condition typically points to a short circuit to ground or abnormally low resistance in the fan drive solenoid circuit.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 5085E
• 5090E
• 5090EL
• 5100E
• 5085M
• 5100M
• 5100MH
• 5100ML
• 5115M
• 5115ML
• 130G
• 130GLC
• 210G
• 210GLC
• 2154G
• 318D
• 320D
• 850K
• 250D
• 300D Series II
• 670G
• 672G

1. 1

   Determine if the DTC periodically goes away to rule out a loose connection versus a hard short.

2. 2

   Inspect the wiring harness and connectors leading to the proportional solenoid valve (variable speed fan solenoid) for signs of physical damage, corrosion, or a direct short to ground.

3. 3

   Use diagnostic tools or a multimeter to measure the circuit current and resistance at the variable speed fan solenoid (Y5005) to verify if the solenoid coil itself has an internal short (low resistance).

1. 1

   Safety First

   Turn off the engine and turn the battery disconnect switch to the OFF position.

2. 2

   Relieve Pressure

   Because this involves the hydraulic fan drive motor, you must relieve all hydraulic pressure before disconnecting any lines to prevent high-pressure fluid injection injuries.

3. 3

   Wiring Repair

   If the diagnostic checks revealed damaged wires or connectors causing the short to ground, repair or replace the affected harness sections.

4. 4

   Solenoid Replacement

   If the solenoid coil failed the resistance test (internal short), replace the variable speed fan solenoid or the entire fan drive solenoid valve assembly. Tighten the locking nuts to OEM torque specifications.

5. 5

   Reassembly

   Reconnect all hydraulic lines and electrical connectors. Turn the battery disconnect switch back to the ON position.

6. 6

   System Test

   Reset the ECU to clear the fault code. Run the machine and perform a system test to ensure the fan operates correctly at variable speeds and the code does not return.