Generator will not start in AUTO mode; controller shows F01 and inhibits crank attempts.

Safety first: Before working on the generator, place the system in OFF, open the main AC disconnect, and if safe to do so, open the battery disconnect. Never work inside the enclosure with the unit capable of auto-start.

• Check emergency stop button: Locate the red emergency stop (E‑stop) pushbutton on the Siemens standby generator enclosure. Verify it is pulled out or rotated to the RUN position. If it is latched in, release it and then clear the alarm on the controller.
• Inspect E‑stop wiring: With power isolated, open the control panel and trace the two low-voltage wires from the E‑stop switch back to the Siemens controller terminal strip (often labeled E‑STOP or ES). Look for loose spade connectors, broken conductors, or corrosion at terminals. Reseat any loose connectors.
• Test switch continuity: Using a multimeter set to continuity, disconnect one wire from the E‑stop switch and test across the switch terminals. In the RUN position the circuit should be closed. If it remains open, replace the E‑stop switch assembly.
• Check controller input: If wiring and switch test good, inspect the controller input terminals for damage or burnt traces. Lightly clean and retighten terminal screws. If F01 persists, the control PCB E‑stop input may be defective and require replacement.
• Reset and test: Restore battery and AC power, set the controller to AUTO, and command a test start. Confirm that F01 is cleared and the unit cranks normally.