John Deere 51.04 – Engine Control Unit (ECU): Engine Air Throttle Valve Position Sensor value Too Low / Air Throttle Actuator Position Signal Out of Range Low

The position signal from the air throttle actuator is below the expected voltage range, typically indicating a short to ground in the circuit due to damaged wiring, insulation wear, or an internal defect in the actuator. This results in limited engine power (derate) and unavailable active exhaust filter (DPF) cleaning.

• 5085E
• 5090E
• 5090EL
• 5100E
• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 5085M
• 5095M
• 5100M
• 5105M
• 5115ML
• 8235R
• 8260R
• 8285R
• 8310R
• 8335R
• 8360R
• 204L
• 304L
• 7400A TerrainCut
• 7760 Cotton Picker / Stripper

1. 1

   Inspect the air throttle actuator wiring harness and electrical connectors for signs of wear, abrasion, or corrosion, especially where wires rub against metal brackets or moisture could enter.

2. 2

   Physically inspect the actuator to see if it is binding or if the internal shaft connecting the actuator to the butterfly valve has snapped.

3. 3

   Use a diagnostic tool (like John Deere Service Advisor) to run a Harness Diagnostic Mode test to evaluate the actuator and its circuitry with the engine off, isolating whether the low signal is from the harness or the sensor.

1. 1

   Repair Wiring

   If the diagnostic tests reveal a short to ground in the harness, repair or replace the damaged section of the wiring.

2. 2

   Replace Actuator

   If the wiring is intact but the actuator fails the diagnostic test or is physically broken, remove the defective air throttle valve assembly from the intake.

3. 3

   Install New Part

   Install the replacement OEM John Deere air throttle valve.

4. 4

   Calibrate

   Use diagnostic software to calibrate the new air throttle actuator so the ECU learns its sweep parameters.

5. 5

   Reset and Test

   Clear the 000051.04 fault code from the ECU. Conduct a comprehensive operational test to ensure the actuator operates within the correct parameters and the engine no longer derates.