Ford 2003 Mustang Owner's Manual page 61

Controls and features
(remote entry transmitters) are brought to the
dealership, to aid in troubleshooting.
Unlocking the doors
Press this control to
unlock the driver's
door. The interior
lamps will illuminate.
Press the control a
second time within five
seconds to unlock all
doors.
Locking the doors
Press this control to
lock all doors.
To confirm all doors
are closed and locked,
press the control a
second time within five
seconds. The doors will
lock again, the horn
will chirp and the lamps will flash.
If any of the doors are ajar, the horn will make two
quick chirps, reminding you to properly close all
doors.
Unlocking the liftgate/trunk
Press the control to
unlock the
liftgate/trunk.
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