Some of the early OBD II systems had a "pin 8". If there is a terminal in pin 8 you can jumper it to pin 4 and it should activate RKE programming.
You might have to turn the key on, it has been a long time since I did it.
To know which pin is pin 8, look at the connector with the fat part on top, the narrow part with the tab in the center on bottom.
Pins 1-8 are on the top row left to right, 9-16 on the bottom.
If you don't see that in your DLC let me know.
1. With the ignition in the "RUN" position (engine does not necessarily need to be running, but it will work either way).
2. Press OFF and WARMER (or the OFF and PASSENGER WARMER buttons) on climate control panel simultaneously. Instrument Panel Cluster (IPC) will light all telltales, then go blank. System is now in DIAGNOSTIC MODE. After diagnostic mode cycles through and stops, press FAN DOWN button until "RFA?" is displayed, then press FAN UP. If "RFA DATA?" is displayed, press FAN DOWN. If "RFA OVERRIDE?" is displayed press FAN UP button.
3. If "RFA S00 NO OVERRIDE" is displayed, press FAN DOWN. If "RFA S01 PROGRAM FOB #1" is displayed, press FAN UP button.
4. IPC will show "0" on right side of Drivers Information Center (DIC) display. Press WARMER button on the climate control unit until "99" is displayed.
5. Press and hold TRUNK button on the transmitter. While holding TRUNK button, press LOCK button and hold both buttons for a total of 3 seconds. Locks will cycle when programming is complete. If transmitter is not programmed within 30 seconds after entering "99" on the display, system will default and you must begin at step #2 again.
6. To program second transmitter, press FAN DOWN button until "RF S02 PROGRAM FOB #2" is displayed, then press FAN UP. Repeat step #4.
7. To exit system, press AUTO, MODE UP, MODE DOWN, or RESET button.