ECU 000027.03 – EGR Valve Position Signal Out of Range High. John Deere Engine Control.

ECU 000027.03 (ECU 27.03)

Code: 000027.03

Shortcode: 27.03


The ECU 000027.03 (27.03) error code on John Deere equipment indicates an issue where the Exhaust Gas Recirculation (EGR) valve position signal exceeds the upper acceptable range. This condition is typically caused by a short to 12 volts within the valve’s electrical circuit. Such a short may result from damaged wire insulation, contact oxidation, or a malfunction within the EGR valve itself. This fault can lead to increased emissions and reduced engine efficiency.


The John Deere engine control system may restrict the operation of the EGR valve or switch to a reduced performance mode to prevent potential engine damage and minimize environmental impact.


  • Inspect Wiring and Connections: Carefully examine the electrical connections and wiring leading to the EGR valve. Look for signs of mechanical damage, wear, or corrosion that could lead to a short circuit.
  • Diagnose the EGR Valve: Utilize specialized diagnostic tools to assess the functionality of the EGR valve. Ensure that the valve operates correctly and does not stick.
  • Replace Faulty Components: If defective components of the EGR valve or its wiring are discovered, replace them with new, original John Deere parts.
  • Error Code Reset and System Check: After repairs or component replacements, reset the error code using diagnostic equipment. Then, conduct a system test to ensure the error does not reoccur and the system operates correctly.


Regular maintenance and diagnostics of the EGR system are crucial to prevent such errors in the future and maintain high levels of fuel efficiency and performance in John Deere engines. Additionally, check the alternator voltage and battery condition, as non-standard power supply voltage can also cause this error to appear.

Control Units: John Deere

John Deere Parts
John Deere Logo