Thanks Pikey, I had some experience with LANs in a former phone company job, now it's just a hobby.
11-10-2012, 11:45 AM
Originally Posted by RayVoy
It's a Local Area Network; actually, may be considered 2 LANs, a high speed network and a low speed network. The low speed is used for the human to vehicle interface (push a door lock button, the door modules lock the doors). The high speed is for the communications between various vehicle control modules and their sub-modules (powertrain, body control, audio, brakes, etc). Most of the modules have 2 states, "awake" and "asleep". An idle state will induce some modules into the "asleep" mode, while others are commanded into that mode. The modules have battery power when the ignition is off, turning on the ignition commands the modules into the "awake" state. Things like the Retain Power feature, are software controlled; these modules stay "awake" for a defined time after the ignition is switched off. At the end of the defined period, the BCM (I think it's the BCM) commands these modules to sleep.
I appreciate the great explanation RayVoy. Thanks to yall that responded to my GMLAN questions. I got everything wired up how I want it now.