check engine light

Does the check engine light have to be on to get the trouble codes? My 1995 corsica's check engine light will come on then go off. Does the light need to stay on to get the trouble codes?

Once the light goes on your computer keeps the code stored. The light is not supposed to stay on all the time, only supposed to light for a few seconds when a problem occurs. You may have only one code that sets over and over or several stored.

Your car is a hybrid between the OBD-I and OBD-II diagnostics, and requires a special adaptor/scan tool to pull the codes. The generic scan tools used at Auto Zone and Advance are not capable of pulling the codes on your car. You will have to take it to a shop that has a GM Tech-II/ Snap-on MT2500 professional type scan tool.