ECU 000051.04 – Air Throttle Actuator Position Signal Out of Range Low. John Deere Engine Control.

ECU 000051.04 (ECU 51.04)

Code: 000051.04

Shortcode: 51.04


The ECU 000051.04 (51.04) error code reflects that the air throttle actuator position signal on John Deere equipment is below the expected range, typically indicating a short to ground. This fault often arises from issues such as damaged wiring, a grounded wire due to insulation wear, or a defect in the actuator itself, leading to a decreased voltage signal.


To mitigate this issue, the John Deere engine control system may restrict the functionality of the air throttle actuator. This is to prevent insufficient air intake that could destabilize engine performance and efficiency.


  • Inspect Wiring and Connections: Carefully check the air throttle actuator wiring and electrical connections for signs of wear, abrasion, or corrosion that could result in a short to ground.
  • Test the Actuator and Electrical Circuit: Employ diagnostic tools to evaluate the actuator and its circuitry for any anomalies that might cause the low signal.
  • Replace Damaged Components: Should any component be identified as defective, replace it with original John Deere parts to maintain system integrity and performance.
  • Reset and Reevaluate the System: After making the necessary repairs, reset the system to clear the fault code. Conduct a comprehensive test to ensure the actuator operates within the correct parameters.


In dealing with ECU 000051.04, it’s important to focus on preventative measures such as regular inspections of the throttle actuator and its wiring. Special attention should be given to potential abrasion points where wires may contact metal parts or where moisture ingress can occur, leading to grounding issues. Scheduled maintenance should include a thorough check of insulation integrity and connector security to prevent recurrence of similar faults.

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