VSS on the PCM

Man, all these accronyms! Can anyone tell me how to find the VSS wire on the PCM of a 2003 Denali? Please keep in mind that I just found out where the PCM is located (under hood, next to fan shroud, driver's side), still don't know what PCM stands for, but I need to find the VSS wire. Appreciate any help.

PCM = Power Control Module.

Can't help you on the VSS wire, sorry.

//2000CAYukon

Thanks. I need all the help I can get on these things nowadays.