ECU 000105.04 – Low Voltage at EGR Mixed Air Temperature Sensor. John Deere System Advisory.

ECU 000105.04 (ECU 105.04)

Code: 000105.04

Shortcode: 105.04


ECU 000105.04 is activated when the input voltage at the exhaust gas recirculation (EGR) mixed air temperature sensor falls below the minimum specified level, typically indicating a short to ground. This fault can lead to inaccurate temperature readings, which are crucial for the ECU to manage the EGR system effectively.


The ECU may alter its responses based on inaccurate temperature data, potentially resulting in suboptimal combustion, increased emissions, or a drop in engine efficiency.


  • Inspect Wiring and Connections: Check the sensor’s wiring and connections for any signs of wear, damage, or corrosion that could lead to grounding issues.
  • Test Sensor Voltage: Use a multimeter to measure the voltage at the sensor to confirm if it is below the expected range.
  • Rectify Electrical Faults: Repair or replace any damaged wiring or connectors.
  • Replace Faulty Sensor: If the sensor or wiring repairs do not resolve the issue, consider replacing the temperature sensor.
  • Reset ECU and Clear Fault Codes: After repairs, reset the ECU and clear any fault codes to ensure the system functions correctly.


A thorough inspection of the EGR system’s electrical components is recommended to prevent recurrence. Regular maintenance helps catch such issues early, reducing the risk of engine performance problems.

Control Units: John Deere

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