Procedure to program a 1998 Mitsubishi Diamante: 1) Open the drivers door 2) Turn the ignition key ON (without starting the vehicle) 3) Press and hold the programming button (located under the dash). In 20 seconds the system will start to cycle the doors and siren 3 times to indicate the system has entered the transmitter learn mode (do NOT release the programming button) 4) Press the 1st button on the un-programmed transmitter. The system will respond by cycling the doors and siren one time to indicate the transmitter has been learned. 5) All other transmitters (up to 4) also need to be programmed at this time 6) Programming is now complete, let go of the programming button and turn the ignition off to exit learn mode.
the dealer does it with a scan tool
On the inside of the keyless entry remote or sometimes on the back it explains how to do this. I believe you hold the unlock button along with the lock button for 7 seconds near the car. It will explain it on the inside of the keyless entry remote.
Take the remote apart and it says to push the buttons once each or twice each try this
My understanding is that you need to have it done at the dealer. There is no way of "cloning" an existing remote onto a second OEM one without dealer tools.
It can have power locks with out keyless.
There should a programming guide in the users manual
Your remote might need replaced, the buttons are probably worn out. They usually don't last for 10 years!
The location of the remote keyless entry module on a 1998 Saturn is in the rear of the passenger compartment. It is underneath the trim at about shoulder height by the right rear seat.
Try turning the ignition on and off about 10 times until the door locks, lock and unlock, then lock with the remote done.
Open the trunk with the master key.
My 98 Ram sport does it is a control module behind the dash if your does not and can be installed quick at the dealer .
25 - 50 bucks at the dealer