get your ecu scanned (unless you wanna crack it open and risk losing your car cuz no more engine management...). i dont think that'll tell which company the chip is from, but anyway. if its apr, you use the cruise control stock only if you have multiple programs. if you have a single program, then the cruise control (cc for short here) stalk wont do anything.
get the cc stalk, switch it to "set" and hold it there for about 3 seconds. your CEL light should start to flash slowly at first. the more programs you have, the longer you can hold it to turn on the other programs. the higher you go in program count, the faster your CEL will blink. once it starts to blink at the right setting (check apr's site) you can let the cc stalk go and your set.
im very iffy on this, havent ridden an apr-chipped car in a while. apr's site has the directions in full.
www.goapr.com