ECU 000028.01 – Primary Analog Throttle Signal Extremely Low. John Deere Engine Control.

ECU 000028.01 (ECU 28.01)

Code: 000028.01

Shortcode: 28.01


The ECU 000028.01 (28.01) error indicates that the primary analog throttle signal is significantly lower than expected, as measured by the foot throttle sensor on John Deere equipment. This condition may stem from a malfunction in the throttle sensor, wiring issues, or an improperly calibrated sensor. A low signal can lead to insufficient engine response or a decrease in engine power, affecting the overall performance and operability of the vehicle.


To manage this issue, the John Deere engine control system may reduce the responsiveness of the throttle or engage a limp mode to safeguard the engine and prevent operational hazards.


  • Inspect and Test Throttle Sensor: Examine the throttle sensor for damage or misalignment. Test sensor output using diagnostic tools to ensure it operates within the designated specifications.
  • Check and Repair Wiring: Look for any signs of wear, damage, or disconnection in the wiring harness that could impact signal integrity.
  • Sensor Calibration or Replacement: Calibrate the sensor if possible; otherwise, replace it with an OEM part if it fails diagnostics.
  • System Reset and Functional Test: After making necessary repairs, reset the engine control system and perform thorough testing under various operating conditions to confirm functionality.


Control Units: John Deere

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