In the 96, I made a jumper to the obd plug with an old OBDI box. I don't remember where I found the proceedure. Anybody remember??? But, before you go to a lot of trouble, my best bet would be that the interior temp sensors are plugged and the little fan is not turning. This will throw a code in the ECC. The temp sensors are located on each side behind the grab handles above the front drivers door and passenger front door. Remove the grab handle, CAREFULLY pull the headliner back and you will see the plug. The fan is held in with one screw...I think torx 25. Pull it out and chances are, it is full of lint and dust. Carefully clean it with tweezers and maybe a Q-tip but be careful not to damage the sensor(the little bulb in the center) Cleaning them fixes most of the problems.