Ford 2003 Mustang Owner's Manual page 73

4. Turn the ignition to OFF and remove the second
SecuriLock key from the ignition.
5. Within 10 seconds of turning the ignition to OFF,
insert the unprogrammed SecuriLock
key/valet key) into the ignition and turn the ignition
from OFF to RUN (maintain ignition in RUN for at
least one second). This step will program your new
SecuriLock key.
6. To program additional SecuriLock
this procedure from step 1.
If the programming procedure was successful, the
new SecuriLock
engine. The theft indicator (located on the
instrument cluster) will light for three seconds and
then go out.
If the programming procedure was not successful,
the new SecuriLock
vehicle's engine. The theft indicator will flash on and
off. Wait at least one minute and then repeat the
procedure from step 1. If failure repeats, bring your
vehicle to your dealership to have the spare
SecuriLock key(s) programmed.
Controls and features
key(s) will start the vehicle's
key(s) will not operate the
key (new
key(s), repeat
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