I found this on the web, but does not seem to work for me. I never get the chime after releasing the UNLOCK+PANIC buttons saying its in programming mode.
Program Method A (Customer Program Method)
1. Press (LOCK) button 5 times at 2 second Intervals to resynchronize transmitter, Attempt to function transmitter, If working as designed discontinue programming.
2. Turn ignition to run position, (Allow Ignition chimes to stop).
3. Using any original (working )transmitter, press the [UNLOCK] button for 4 to 10 seconds.
4. Within the specified 4 to l0 seconds, continue pressing the [UNLOCK] button and press the [PANIC] button for 1 second and release both buttons (AN/DN release either button first). A chime will sound to indicate that the transmitter programming mode has been entered (allow 3 seconds for chime to sound).
5. Press [LOCK] and [UNLOCK] buttons simultaneously for 1 second and release (a short chime will sound for AN/DN).
6. Press and release any button an the same transmitter and a chime will sound after successfully programming the transmitter (locks will cycle for AN/DN).
NOTE.- (FOR DR ONLY) A CHIME WILL NOT SOUND ON STEP #6 FOR THE FIRST TRANSMITTER PROGRAMMED, BUT WILL SOUND UPON PROGRAMMING THE SECOND TRANSMITTER.
7. Repeat steps 5 through 6 to program additional transmitters.
8. Turn ignition to OF:F position. Transmitter programming mode will discontinue after 60 seconds (30 seconds for AN/DN and RS). (All transmitter programming must be completed within time specified).