Generator controller displays E18 and the unit will not start; a key or security icon may be shown.

Safety first: Ensure the generator is OFF and cannot auto-start.

• Check controller mode: Verify the Firman controller is not in a LOCKED or SERVICE mode. Follow the user manual to exit maintenance lockout if recently serviced.
• Power cycle controller: Disconnect battery negative for 2–3 minutes, then reconnect to reset the controller. Re-enter date/time and configuration if required.
• Review remote monitoring: If a remote monitoring or Wi-Fi module is installed, check its app or interface for any active lockout commands. Clear them.
• Consult manual for code reset: Some controllers require a specific key sequence or password to clear E18. Follow Firman instructions exactly.

If E18 cannot be cleared or reappears immediately, the controller may be defective and should be evaluated or replaced by an authorized Firman service provider.