ECU 000101.04 – Crankcase Pressure Signal Out of Range Low. John Deere Engine Control.

ECU 000101.04 (ECU 101.04)

Code: 000101.04

Shortcode: 101.04


The ECU 000101.04 (101.04) error code indicates that the crankcase pressure sensor signal on John Deere equipment is unexpectedly low, pointing to a potential short to ground in the sensor’s circuit. This electrical fault can cause the sensor to transmit inaccurately low pressure readings, which may not reflect the actual conditions within the engine’s crankcase. It’s critical to consult the relevant Component Technical Manual (CTM) for specific diesel engines to follow precise diagnostic procedures.


In response to this error, the engine control system might underestimate crankcase pressure, potentially failing to alert to actual conditions that require attention, such as excessive crankcase pressure that could indicate underlying engine issues.


  • Consult the Component Technical Manual (CTM): Follow the detailed diagnostic procedures outlined in the CTM specific to your engine model.
  • Inspect Sensor Wiring and Connections: Examine the crankcase pressure sensor’s wiring and electrical connections for any signs of damage or wear that could cause a short to ground.
  • Test the Crankcase Pressure Sensor: Use diagnostic tools to evaluate the sensor’s functionality and to verify that the low signal is due to a wiring or sensor fault, not an actual engine condition.
  • Repair or Replace Faulty Components: If the sensor or its wiring is found to be faulty, replace them with OEM parts to ensure proper functionality and compatibility with the engine control system.
  • Reset the System and Conduct a Test: After making necessary repairs, reset the engine control unit to clear the error code and perform tests to ensure that the crankcase pressure readings are accurate and reliable.


Regular inspection and maintenance of engine sensors and their associated wiring are crucial for accurate operation. A short to ground can significantly affect sensor performance, leading to improper engine management decisions. Ensuring that all connections are secure and free from corrosion or damage helps maintain sensor accuracy and reliability. Additionally, following the recommended diagnostic and repair procedures in the CTM ensures that the work is done correctly and effectively, safeguarding engine health and performance.

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