Generator cranks but fails to start; controller shows F03 Overcrank after several attempts.

Safety first: Set the controller to OFF and disable automatic start. Keep clear of moving parts during crank attempts.

• Verify fuel supply: For natural gas or LPG models, ensure the gas supply valve to the generator is fully open and that upstream gas shutoff valves are not closed. For diesel models, check the fuel tank level and open any inline shutoff valves.
• Check gas pressure or diesel delivery: For gas units, confirm with your gas provider or a technician that line pressure meets Siemens specifications at the generator regulator inlet. For diesel units, inspect the fuel filter and lines for leaks or air bubbles in clear sections.
• Inspect fuel solenoid: Locate the fuel shutoff solenoid on the engine. During a crank attempt, listen or feel for a click as it energizes. If there is no click, check the solenoid connector and fuse. Replace the fuel solenoid if it does not energize with proper voltage present.
• Check battery condition: Measure battery voltage at rest; it should be around 12.6 V (for 12 V systems). If below 12.0 V, charge or replace the battery. Clean and tighten battery terminals and the ground strap to the frame.
• Clear code and retest: After addressing fuel and battery issues, clear F03 on the controller and attempt a manual start. If the engine still fails to fire, spark plugs (gas) or injectors (diesel) may require service by a technician.