pulling codes

You don't need a scan tool to pull these codes.

Here is a guide that will help with this, and it has good info that will help.

https://www.2carpros.com/articles/buick-cadillac-chevy-gmc-oldsmobile-pontiac-gm-1983-1995-obd1-code-definitions-and-retrieval-method

Below you will find the wiring diagram and explanation on how to pull the codes. Basically, if you jump any of these ports to the ground terminal with the key on you will get codes if there are any in these modules.

Please run through this info and let us know what questions you have.

Thanks