Generator will not start; controller shows Fault Code 111 – Overcrank
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety first: Standby generators can start automatically. Disable automatic start before working. Set the Cummins controller to OFF or STOP, open the main DC breaker if equipped, and isolate AC output at the transfer switch. Do not work near moving parts.
- Check fuel supply: Verify the gas shutoff valve (natural gas or LPG) to the generator is fully open. For diesel units, confirm the day tank has fuel and the fuel shutoff valve is open.
- Inspect for air in fuel: On diesel models, use the manual priming pump (if fitted) and bleed screws on the fuel filter housing to remove air. Tighten fittings and check for leaks on the fuel supply line and return line.
- Battery condition: Measure battery voltage at the battery terminals; Cummins standby sets typically require around 12.6 V (12 V system) or 25.2 V (24 V system) at rest. Clean and tighten battery terminals and ground strap. If voltage is low, charge or replace the starting battery.
- Starter operation: Have an assistant attempt a start while you listen for the starter. If you hear a click but no crank, suspect the starter solenoid or starter motor. Check the starter relay and related fuses in the control panel.
- Clear the fault: After correcting issues, reset the controller (usually by pressing STOP/RESET then AUTO) and attempt a start again.
If the engine still will not crank or start, further diagnosis of the starter circuit and fuel system by a Cummins technician is recommended.