Select A Vehicle
1998 - 2002 Mercury Grand Marquis
Must Have 2 Original Working Keys
1. Insert an existing working key into the ignition cylinder.
2. Turn the ignition cylinder to ON (RUN) and back to OFF.
3. Remove the existing working key and, within five seconds, insert a second working
key and turn it to ON (RUN) then back OFF.
4. Remove second working key and insert the new key before ten seconds have
elapsed and turn it to ON (RUN). Leave it on for one second and turn back to OFF.
5. The security light will light up for three seconds to indicate that the new
key has been successfully programmed.