Looking at the PIDs listed under the 2001 OS (12212088) and noticed that there appears to be several different groups. I understand the SAE PIDS which are listed as 00xx (example 0011 is the TPS %). The next group has a prefix of 11 (example 1140 - which I have seen referenced as MAF signal). There are quite a few PIDs which start with 11xx, 12xx and 13xx. I found one reference from an earlier non LS OS (believe it might have been a vortec black box PCM) which listed some of these PIDs. It appears that some of the names match up, but some of them do not.


The next grouping has a 19xx prefix (and three 1Axx PIDs). Are these transmission PIDs? The one reference I found lists some 19xx PIDs and these have to do with the transmission variables.


The final group of PIDs has a FCxx prefix. For these I have not seen any mention of what they pertain too.


Is there a master list that can be referenced? I looked over the SAE documentation, but it obviously only covers the 00xx PIDs. And GM only threw in a few of those. The main section is the 11xx through the 19xx (and maybe the FCxx). I think that some / all of these are what are called "Enhanced PIDs". If so, then maybe the only documentation for them would have to come from GM.