BCU 000186.17 – Rear PTO Speed Sensor No Signal. John Deere System Advisory.

BCU 000186.17 (BCU 186.17)

Code: 000186.17

Shortcode: 186.17


Error code BCU 000186.17 is triggered when the Basic Control Unit (BCU) of a John Deere vehicle detects that the rear Power Take-Off (PTO) is activated, yet no speed signal is transmitted by the rear PTO speed sensor (B06). This issue can arise either because the sensor is failing to detect motion despite the PTO being engaged, or because the PTO is turned on without a speed setting being selected. This can indicate a sensor malfunction or a communication error within the PTO system.


The BCU will likely respond by issuing a fault alert and may inhibit PTO operation until the issue is resolved, to prevent damage to the machinery or ensure operational safety under uncertain mechanical feedback.


  • Check PTO Engagement and Settings: First, ensure that the PTO is properly engaged and that a speed setting is indeed selected. This check helps determine if the issue is operational or mechanical.
  • Inspect PTO Speed Sensor and Connections: Examine the PTO speed sensor for signs of damage, dirt, or misalignment that could prevent it from detecting shaft movement. Also, check all electrical connections for tightness and corrosion.
  • Test Sensor Functionality: Utilize diagnostic equipment to test the functionality of the PTO speed sensor. Ensure it is capable of detecting and accurately reporting shaft speed.
  • Verify Wiring and Circuit Integrity: Check the wiring harness for breaks, shorts, or other damage that could interfere with signal transmission from the sensor to the BCU.
  • Replace Faulty Sensor: If diagnostics confirm the sensor is faulty, replace it to restore proper functionality to the PTO system.
  • Reset the BCU and Clear Diagnostic Codes: After repairs or adjustments, reset the BCU to clear any stored fault codes and retest the system to confirm the issue is resolved.


Ensuring that the rear PTO speed sensor and related components are functioning correctly is crucial for the safe and efficient operation of PTO-driven implements. Regular maintenance and timely repair of these components help maintain the reliability and productivity of your John Deere equipment, reducing potential downtime and operational disruptions.