Description:

This diagnostic trouble code (DTC) UIC 000974.03 is generated when the control unit measures a voltage of more than 4.5 volts at the signal input from channel 1 of the hand throttle potentiometer (B78, lead 6077). This indicates a problem either at the signal lead or at the potentiometer ground connection.

Reaction:

When this error occurs, the control unit may limit throttle response or activate a fail-safe mode to ensure vehicle safety and prevent potential damage.

Recommendations:

• Inspect Signal Lead and Connections:
  • Check the wiring connections at the hand throttle potentiometer for any loose, corroded, or damaged connectors.
  • Measure the voltage at lead 6077 to confirm it exceeds 4.5 volts.
• Inspect Ground Connection:
  • Ensure the ground connection of the potentiometer is secure and free of corrosion or damage.
• Replace Hand Throttle Potentiometer:
  • If the wiring and connections are intact and the voltage remains too high, consider replacing the hand throttle potentiometer (B78).
• Consult Technical Support:
  • If the issue persists, contact John Deere technical support for further assistance and potential software updates.

Note:

• High 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 error code occurrences and the conditions under which they happen can help in diagnosing intermittent issues.