there are a few methods depending on the model, these are the ones I have found:
Remote Key Registration Procedure:
1) Switch ignition ON.
2) Insert key to be programmed into driver’s door lock.
3) Lock vehicle manually (rotate key in lock)
4) Press lock or unlock button on new key.
5) Wait at least 1 second.
6) Press lock or unlock button again.
7) Vehicle horn sounds briefly to indicate successful programming
method 2:
1 ignition on to red lights on dash
2 turn off immediately and pull key out
3 hold 1 of the buttons down (dont matter which)
4 PRESS the other 3 times ( with a SLIGHT pause) 1 . 2 . 3
5 watch led on key (should flash) and doors usually try lock/unlock
6 turn ignition key back on to red lights and wait 5 sec
7 key out again and test operation
method 3:
1 Take the valet key, put it into the ignition and turn the key to the "on" position, just prior to starting the car.
2 Roll down the driver's side window (not required, but a good idea in case there's a problem).
3 Exit the car and close the door.
4 With a second key, physically lock the doors (don't use a remote).
5 Take the first remote to be programmed, press one of the buttons and the lights will flash once. Wait 10 seconds and press the unlock button. The doors should unlock. That first transmitter is now programmed.
6 Lock the door again (physically) with the key, (not the remote).
7 Press one of the buttons twice, the lights will flash twice. Wait 10 seconds and press the unlock button. The doors should unlock. The second transmitter is now programmed.
For a third transmitter press the button 3 times and for a fourth press 4 times.
