John Deere 523806.12 – BCU: Y75 Solenoid for PTO Speed 3 Off, Current Present at Power Module PC5

The Basic Control Unit's Power Module (PC5) detects a current flow of more than 1 amp at the output for the Y75 solenoid (which controls PTO Speed 3) even though the system has commanded the solenoid to be OFF. This indicates a short to power in the wiring, a faulty solenoid, or an internal failure within the Power Module PC5 itself.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6230R
• 6250R
• 6110M
• 6120M
• 6130M
• 6140M
• 6145M
• 6155M
• 6175M
• 6195M
• 6230
• 6330
• 6430
• 7130
• 7230
• 7430
• 7530

1. 1

   Inspect the wiring harness running from the BCU/Power Module PC5 to the Y75 PTO Speed 3 solenoid. Look for chafed wires that may be shorting to a 12V power source.

2. 2

   Disconnect the electrical connector at the Y75 solenoid and turn the key ON (engine off). If the code changes to an 'Open Circuit' or 'No Current' code (like BCU 523806.05), the short is likely internal to the solenoid. If the 523806.12 code remains active, the short to power is in the wiring harness or the PC5 module itself.

3. 3

   Check the output pin at the PC5 module for the Y75 solenoid. If it is outputting voltage when the PTO is commanded off, the Power Module may have a stuck internal driver/relay and require replacement.

1. 1

   Prep the Machine

   Park the tractor on a level surface, engage the parking brake, turn off the engine, and disconnect the negative battery cable.

2. 2

   Locate the Solenoid

   Locate the rear PTO valve block on the rear chassis. Identify the Y75 solenoid (PTO Speed 3).

3. 3

   Remove the Solenoid

   Disconnect the wiring harness connector from the solenoid. Clean the area around the valve to prevent dirt from entering the hydraulic system. Unbolt/unscrew the solenoid cartridge from the valve block.

4. 4

   Install the New Part

   Lubricate the O-rings on the new solenoid with clean hydraulic oil. Thread the new solenoid into the valve block and torque to OEM specifications.

5. 5

   Reconnect and Test

   Reconnect the electrical harness. Reconnect the battery. Clear the BCU fault codes using a diagnostic tool, start the tractor, and cycle the PTO through its speeds to verify the repair.