Description:

This diagnostic trouble code (DTC) UIC 000091.04 is generated when the control unit measures a voltage of less than 0.5 volts at the signal input from channel 1 of the accelerator pedal potentiometer (B79, lead 6066). This indicates a problem at the signal lead or an issue with the potentiometer supply voltage.

Reaction:

When this error occurs, the control unit may limit the engine performance to prevent unsafe operation, potentially resulting in reduced acceleration or a “limp mode” to ensure the vehicle remains controllable.

Recommendations:

• Inspect Signal Lead and Connections:
  • Check the wiring connections at the accelerator pedal potentiometer for any loose, corroded, or damaged connectors.
  • Measure the voltage at lead 6066 to confirm it is below 0.5 volts.
• Verify Potentiometer Supply Voltage:
  • Ensure that the supply voltage to the potentiometer is within the specified range and is not causing the low voltage reading.
• Replace Accelerator Pedal Potentiometer:
  • If the wiring and connections are intact and the voltage is still too low, consider replacing the accelerator pedal potentiometer (B79).
• Consult Technical Support:
  • If the issue persists after these checks, contact John Deere technical support for further assistance and potential software updates.

Note:

• Low voltage readings could also be due to intermittent faults in the wiring or connectors. Ensure a thorough inspection to avoid repeat occurrences.
• Keeping a log of the error code occurrences and the conditions under which they happen can help in diagnosing intermittent issues.