ECU 000029.03 – Secondary Throttle Signal Out of Range High. John Deere Engine Control.

ECU 000029.03 (ECU 29.03)

Code: 000029.03

Shortcode: 29.03


The ECU 000029.03 (29.03) error code signals that the secondary throttle signal 3 on John Deere machinery exceeds the high voltage threshold specified for this sensor. This abnormal high voltage can be indicative of issues such as electrical interference, a malfunctioning throttle sensor, or a fault within the wiring or connections that artificially elevates the signal.


In response to this error, the engine control system may limit the function of the throttle to prevent erratic engine behavior or potential over-speeding, safeguarding both engine health and operator safety.


  • Inspect and Test Sensor and Wiring: Examine the throttle sensor and its associated wiring for signs of damage, corrosion, or improper connections that might cause high voltage readings.
  • Diagnose Electrical Interference: Check for sources of electrical noise or interference that could affect the sensor’s signal.
  • Replace Defective Parts: If the sensor or any part of its wiring is found to be defective, replace them with genuine John Deere parts to ensure proper functionality.
  • Reset System and Verify Operation: After resolving the issue, reset the engine control system to clear the error and perform a detailed test to ensure the throttle functions normally under all operational conditions.


For the ECU 000029.03 error, it is critical to also consider the impact of environmental factors such as extreme temperatures or electromagnetic fields from nearby equipment which may affect sensor performance. Regular environmental checks can help identify these issues before they lead to faults.

Control Units: John Deere

John Deere Parts
John Deere Logo