The problem with 1996 DIC is that the 1996 cars are OBD II and GM only made about 900 or so DIC for that year. Most of the ones you find for sale are for 94-95 OBD 1.5 cars. The computers are different so they have trouble figuring out the information.

You need a temp sensor. It's located behind the bumper and infront of the radiator on the middle support below the hood latch mech. You car should be pre-wired for that and you will just need to plug in the temp sensor.