Security indicator light
Nissan Altima / Nissan Altima Owners Manual / Instruments and controls / Warning/indicator lights and audible reminders / Indicator lights / Security indicator light

This light blinks when the ignition switch is placed in the OFF, LOCK or ACC position.
The blinking security indicator light indicates that the security systems equipped on the vehicle are operational.
For additional information, see “Security systems” later in this section.
See also:
Engine oil and oil filter recommendations
...
Brakes
If the brakes do not operate properly, have the
brakes checked by a NISSAN dealer. ...
Supplemental air bag warning light
SUPPLEMENTAL AIR BAG
WARNING LIGHT
The supplemental air bag warning light,
displaying
in the instrument panel, monitors
the circuits of the supplemental front-impact
air bag, front seat ...
