Pcm

My bro has an 02 firebird and he wants to run wires through the firewall. It said something about the PCM and I don't really understand that. I already searched and came up with nothing... I was wondering, what unabbreviated form of PCM and what does it mean/do?
Thanks,
Mark.

I don't know what it stands for but the PCM is the "brain" of the car. It's the computer that runs everything basically. It's the metal box in the upper passenger side corner under the hood. I circled it in the following picture. http://files.automotiveforums.com/gallery/watermark.php?file=/503/148172pcm-med.JPG



http://shbox.com/1/4th_gen_tech1.html has a guide on how to route wires, which I've used seversl times, but the link isn't working right now for some reason.

thanks alot! You helped a bunch!
Thanks,
Mark

It stands for Powertrain Control Module, it use to be called the ECM for Engine control module but in 94 + vehicles the computer also controls transmission functions therefor powertrain became the new term