actually the procedure is made to resync your key with the alarm brain
not add a new one
as from the manual
" open the drivers side door, others closed
using the door lock control switch
perform " lock , unlock " operation 10 times within 30 seconds
keep each state for about 1 second
less than 2 seconds after performing the above
continue to press the transmitter switch for 10 seconds
does nothing
if it locks 2 time the codes do not match the rom and ecu
3 times transmitter fault