Keyless programming for 97+ DSM's
To reprogram your keyless entry system for a new key fob:
 1) Turn ignition to OFF.
 2) Ground pin 1 of the Data Link Connector (black 16-pin connector under dash driver's side). Pin 4 of this connector is a ground, so placing a jumper wire between pins 1 & 4 will accomplish this. Grounding pin 1 tells the system you are getting ready to reprogram it.
 3) Close all the doors.
 4) Turn the key to ACC, then back to OFF. The power locks will lock/unlock. The system is now ready to be programmed.
 5) Press a button on your key fob.
 6) If you have two key fobs, press a button on the second fob within 1 minute of pressing a button on the first one. Both must be programmed at the same time. If you only have one remote, press a button on it 2 more times to signal that you only have one.
 7) The doors will lock/unlock to signal that the codes were received.
 8) Remove the connection between pins 1 & 4.