ECU 000029.04 – Secondary Throttle Signal Out of Range Low. John Deere Engine Control.

ECU 000029.04 (ECU 29.04)

Code: 000029.04

Shortcode: 29.04


The ECU 000029.04 (29.04) error code indicates that the secondary throttle signal 3 on John Deere equipment is below the low voltage threshold for this sensor. Causes can include a faulty throttle sensor, degraded wiring, or poor electrical connections that result in a reduced voltage signal.


The engine control system may trigger a safety mode to reduce engine power, effectively preventing any unpredictable or insufficient throttle response that could compromise safety or engine performance.


  • Check Sensor and Electrical Connections: Carefully inspect the throttle sensor and all electrical connections for wear or damage that could result in low voltage signals.
  • Measure Sensor Output: Use diagnostic tools to check the output from the throttle sensor to confirm that it falls within the expected range.
  • Repair or Replace Damaged Components: Any damaged components should be repaired or replaced with original John Deere parts to restore normal operation.
  • Reset and Test the System: After repair or replacement, reset the engine control system and thoroughly test the throttle to ensure it responds appropriately across all ranges.


For ECU 000029.04, be aware that low signal issues may also indicate broader system voltage problems, such as issues with the vehicle’s battery or alternator. Regular system-wide voltage checks can prevent misdiagnoses and ensure the throttle sensor receives the correct power supply.

Control Units: John Deere

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