EPC 000091.03 – B79 Accelerator Pedal Potentiometer, Voltage Too High

EPC 000091.03 (EPC 91.03)

Code: 000091.03

Shortcode: 91.03


This error code, EPC 000091.03, indicates that the control unit has detected a voltage exceeding 4.7 volts at the signal input of the accelerator pedal potentiometer (B79). This high voltage condition suggests that the circuit may be shorted to a supply lead or is open.


When this error is detected, the control system may not accurately interpret the position of the accelerator pedal, leading to potential issues with throttle response and engine performance. This can result in erratic or unresponsive acceleration.


Inspect Wiring for Shorts:

  • Check the wiring associated with the accelerator pedal potentiometer for any signs of short circuits to the supply lead. Look for damaged insulation or exposed wires.

Test Potentiometer Functionality:

  • Use diagnostic tools to test the accelerator pedal potentiometer (B79). Ensure it is functioning correctly and providing accurate voltage readings.

Verify Connections:

  • Inspect all connectors and terminals in the circuit for secure and clean connections. Repair or replace any that are loose or corroded.

Check for Open Circuits:

  • Ensure that there are no open circuits in the wiring leading to the potentiometer. Use a multimeter to test for continuity.

Reset and Test System:

  • After addressing any issues found, reset the system and test the accelerator pedal response to ensure the problem is resolved.


Regular inspection and maintenance of the wiring and potentiometer can help prevent such voltage-related issues. Ensuring secure and clean connections is crucial for accurate sensor readings and optimal performance.

Control Units: John Deere

John Deere Parts
John Deere Logo