John Deere 523812.09 – RPT / BCU: CAN BUS Message Fault Rear Chassis (RPT) / Incorrect CAN BUS Message for Y74 Solenoid, PTO Speed 2

Communication error on the vehicle's CAN bus network involving intermittent or nonexistent reception of CAN messages transmitted by the control software to the power module (PC5) regarding the Y74 Solenoid (PTO Speed 2). Because the module cannot verify the status or command for the PTO Speed 2 solenoid, the functionality of the rear PTO is significantly limited or entirely disabled as a safety precaution.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6230
• 6330
• 6430

1. 1

   Cycle the power by turning the key switch off and back on to see if the communication error was a momentary glitch.

2. 2

   Inspect the CAN Bus wiring harness and connectors between the Rear Chassis Control Unit (RPT), the Body Control Unit (BCU), and Power Module PC5 for chafing, corrosion, or loose pins.

3. 3

   Inspect the Y74 Solenoid (PTO Speed 2) circuit wiring for open circuits or shorts to ground.

4. 4

   Test current and voltage levels at the Y74 solenoid when activated using a multimeter or Service ADVISOR (system expects above 500 mA).

5. 5

   Verify that the PAP (Power-Assisted PTO) control software is updated to the latest version to rule out software bugs.

1. 1

   Disconnect Power

   Disconnect the tractor's battery to prevent electrical shorts during repair.

2. 2

   Repair Wiring/Connectors

   If the diagnostic checks revealed damaged wiring or corroded connectors on the CAN bus lines or the Y74 solenoid circuit, splice in new wiring or replace the damaged connector pins.

3. 3

   Replace the Y74 Solenoid

   If the wiring is intact but the solenoid failed the current/resistance test, locate the Y74 solenoid on the rear PTO valve block. Remove the retaining hardware, unplug the electrical connector, and extract the solenoid. Install the new solenoid and torque to OEM specifications.

4. 4

   Replace Power Module PC5

   If the wiring and solenoid are good, but the PC5 module is failing to send/receive CAN messages (internal fault), the module itself must be replaced.

5. 5

   Reassemble and Update

   Reconnect the battery. If a new module was installed, use John Deere Service ADVISOR to program the module to the tractor. Ensure the RPT/PAP software is flashed to the latest version.

6. 6

   Clear Codes and Test

   Clear the 523812.09 fault code. Start the tractor and engage the rear PTO (specifically Speed 2) to verify that the code does not return and the PTO operates normally.