OBD-II GM Codes Options

[impala454]

Ok so I know this is a longshot but a couple of you guys on here are car people. I am working on an OBD-II program for my truck and have gotten all the standard data ("Mode 01") from the computer without any probs, but am having trouble finding any documentation online for specific models enhanced mode data ("Mode 22", "Mode 24", etc).

if you have no clue what I'm talkin about, here's the rundown: every car made since 1996 (and a few pre 96) has an OBD port (on-board diagnostic). it's basically just a modified serial port, but is standardized across all cars for the basic information. the basic data you can access (aka mode 01) is stuff like trouble codes, engine load, fuel trim, O2 sensor data, rpm, speed, and lots of others. where they split off into different codes is by manufacturer and sometimes model apparently. the enhanced modes can give you data for just about everything else in the car, door open sensors, selected gear, window/door lock controls status, anything you can think of. this is the data i'm looking for and if any of you know a GM mechanic they might have a listing of all these codes. anyhow like i said i'm sure it's a stretch to ask here but i figure what the hell it's worth a shot.