ECU 000051.03 – Air Throttle Actuator Position Signal Out of Range High. John Deere Engine Control.

ECU 000051.03 (ECU 51.03)

Code: 000051.03

Shortcode: 51.03


The ECU 000051.03 (51.03) error code indicates that the air throttle actuator position signal on John Deere equipment is out of the high range, typically due to a short to 12 volts. This fault suggests a potential wiring issue or electrical fault within the throttle actuator circuit, where the voltage exceeds the normal operational range, possibly due to damaged insulation or a fault in the actuator itself.


In reaction to this error, the John Deere engine control system may limit the operation of the air throttle actuator to prevent excessive air intake, which could lead to uncontrolled engine speeds and potential damage.


  • Inspect Wiring and Connections: Thoroughly check the wiring and connections to the air throttle actuator for signs of damage, corrosion, or improper connections that might lead to short circuits.
  • Diagnose the Actuator and Circuit: Use diagnostic equipment to test the actuator and the associated circuitry to identify the source of the high voltage.
  • Replace Faulty Components: If a damaged wire or faulty actuator is identified, replace it with genuine John Deere parts to ensure proper functionality and compatibility.
  • Reset the Error Code and Test the System: After repairs, reset the error code and perform operational tests to confirm the system is functioning correctly and the fault does not reappear.


For ECU 000051.03, regular electrical system checks are crucial, especially in environments prone to moisture or chemical exposure, which can accelerate corrosion and electrical faults. Ensure that all electrical components are sealed and protected to prevent similar issues in the future. Also, consider implementing a routine check-up schedule that includes inspection of all throttle-related components to avoid recurrence of such faults.

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