See Controls and Indicators → Instrument Lamps → Indicator Lamps. The security system lamp in the speedometer face indicates the status of the Harley-Davidson Smart Security System.

Armed: A lamp that blinks approximately every 3 seconds indicates that the system is armed.
Disarmed: After the system disarms and the ignition is on, the lamp will remain illuminated for approximately four seconds and then turn off.
Service: A lamp that remains illuminated longer than four seconds while the system is disarmed indicates that the module needs servicing.