ECU 000636.08 – Pump Position Sensor Input Missing. John Deere System Advisory.

ECU 000636.08 (ECU 636.08)

Code: 000636.08

Shortcode: 636.08


This diagnostic trouble code, ECU 000636.08, indicates that the input signal from the pump position sensor is missing, implying that the ECU cannot detect camshaft speed. This failure can significantly impact engine management and timing.


The absence of the pump position sensor input may lead to improper engine timing adjustments, potentially causing engine misfires or reduced engine performance.


  • Check Sensor Connectivity: Ensure that the pump position sensor is properly connected and the wiring harness is intact.
  • Test Sensor Functionality: Conduct tests to determine if the sensor is operational or needs replacement.
  • Inspect Related Components: Verify that other related components and systems are functioning correctly and are not contributing to the loss of sensor input.
  • Reset ECU and System Tests: After addressing the issue, reset the ECU and perform a comprehensive test to ensure the camshaft speed signal is consistently detected.


Timely restoration of sensor input is vital to maintaining engine performance and avoiding further complications.

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