Originally posted by ijames
What it shows is that the closed loop enable flag is set. This tells the ecm that the engine has met all of the run time, coolant temp, and o2 activity thresholds so that it is okay to actually go into closed loop whenever it's not in some other special mode such as pe, de, dfco, or ae. So the ecm can't go into closed loop mode if that flag is not set, but having it set does NOT mean that the ecm IS in closed loop mode. Same flag is sent in the aldl data stream so all scan tools there follow the same logic.
Dave, are you forgetting my old posts on the chunk of code that controls the fan (I think you had a post or two on that thread as well)? GM has a logic error and the mph test never gets done; it's in the rom so we can't fix it. I tried to copy it from the gnttype archives but that seems to be down right now, and if it was here it was before that big crash so it's gone.
I knew there was a logical reason but, as you said, I forgot about the code glitch.
