The scan indicates the brake and body control module are a problem. The Engine Check light works on bulb check but doesn't come on for these errors. Basically the car runs well, including ABS. Flaky errors like remote works doors sometimes, no cruise, and no interior lights on door open. Oil pressure reads Normal @ 128 psi, engine on or off. And so on...

I recently acquired this vehicle with 82k miles. Perhaps someone could recommend a good manual to track these items down. And any suggestions would be welcome.

Thanks much.

Check engine light will only come on with some error codes. This is designed by GM.

Lets work the basics first and verify that your battery connections are tight and corrosion free. Next, though I'm not sure if this applies to your car, but worth a read...https://www.gmforum.com/electrical-1...1999-a-303224/

Thanks Mike. The basics are good. I should also note the battery state is displayed as "????". I'll do the check and the read, and let you know what I get.

When I got my 97 PA there were codes, some stuff acting like yours in some instances.
I had few fuses that were questionable, one was the power accessories plug in up front and I used a VOM to test each fuse under rear seat & up front. Replaced the AC relay module as well. Even though I had 14.5 volts going into the Delco battery at idle....
I load tested the Delco 800cca battery at a local service centre that had a Midtronics Hand held load tester..my battery read low on voltage and was down to 480cca CCA .
I replaced the battery with the best, an Odyssey AGM type and all is well again.
The PK Ave has tons of lights on, just when u open the doors, and constant drains, so I felt it important to use a high capacity like the odyssey that keeps the headlights burning bright in most conditions. Everything seems to work better and faster (windows) with this battery and I do not seem to suffer the glitches like I use to. In other words these types of cars need a good battery and charging system, otherwise things can sometimes get real strange with a weakening battery or charging system.
When it is cold out...

A real CCA Battery makes a real difference!

Never get corrosion on terminals again with this absorb glass matt sealed battery!
New clean cables ensure power gets delivered properly.

Let there be real strong power!