John Deere 524218.31 – CCU: CAN BUS Message Fault - Park Lock Fault / Park Position Signal Fault

The control software has detected an open circuit at the park position sensor, or the park position signal cannot be determined and provided on the CAN bus. When this error is active, the system transmits a replacement value, which typically results in the rear PTO and certain transmission functions being significantly limited or entirely disabled for safety.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6090MC
• 6100MC
• 6110MC
• 6090RC
• 6100RC
• 6110RC

1. 1

   Inspect the wiring harness and connectors leading to the park position sensor for signs of an open circuit, chafing, or corrosion.

2. 2

   Test the park position sensor/switch for proper continuity and operation when the lever is moved in and out of park.

3. 3

   Check the park lock actuator/solenoid valve circuit for open connections or shorts to ground.

4. 4

   Ensure that CAN messages from the transmission control software (PTA, PTQ, or PTD) are being correctly transmitted to the CCU.

1. 1

   Safety First

   Park the tractor safely on level ground, block the wheels (since the park lock system is compromised), turn off the engine, and disconnect the battery.

2. 2

   Access the Components

   Locate the park position sensor and the park lock solenoid valve, which are typically mounted on or near the transmission housing/rear axle.

3. 3

   Wiring Repair

   Disconnect the sensor and inspect the pins. Clean any debris or moisture. If you find broken wires or a damaged connector (a common cause for the "open circuit" trigger), repair or replace the damaged wiring harness section.

4. 4

   Component Replacement

   If the wiring is intact but the sensor fails continuity testing, replace the Park Position Sensor. If the sensor is functioning but the transmission will not physically lock/unlock and the code persists, replace the Park Lock Actuator/Solenoid Valve.

5. 5

   Software Update

   Reconnect the battery. Ensure that the CCU, PTA, and RPT control software are flashed to the latest versions to patch known communication bugs.

6. 6

   Clear and Test

   Clear the fault codes using a diagnostic tool and cycle the tractor through park, neutral, and drive to verify the code does not return and PTO functions are restored.