to program new (or second hand) remote keys into your central locking, you need the 4 digit code from a remote key that is already programmed to work. that would include either of the 2 original remote keys.
what code? i hear you asking yourself. each remote key has its own 4 digit code. this code is on a small keyring when new, as shown in the following pic.
fiat did not keep a register of these codes, so if your codes are missing, they're missing for good. if you buy new keys, even with their codes, you still cant program them into your central locking unless you have the code from a remote that has already been programmed in to the central locking.
to program a remote you simply:
-Press the button that is between your courtesy light and the ultrasonic sensors on the roof of your car (near sunroof switch)
-Release the button after a second or two
-After a couple of seconds the LED will flash once
-Enter the first digit of your 4 digit code by pressing the button the relevant number of times
-After a couple of seconds the LED will flash once
-Repeat this for the next 3 digits of the code.
If the code was correct the LED will flash for approximately 10 seconds.
(If the code was incorrect the LED will remain on for 10seconds, so start from the beginning when the LED goes out)
-With the LED flashing press and hold the button on the car and then press and hold the button on the key. Keep them both pressed until the LED stops flashing and remains on.
-Release the button on the remote, then the one on the car.
now what heppens next depends on the age of the car. some cars have a red LED others have a green LED.
for a red LED, if the programming was successful the LED will flash 6 times, but if it was unsuccessful the LED will flash 18 times
for a green LED, if the programming was successful the LED will flash 8 times (i think, maybe less), but if it was unsuccessful the LED will stay on for a few seconds (8 i think?)