Circuit/System Description

The devices connected to the object high speed GMLAN serial data circuits (circuit numbers 3811 & 3813) monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the devices when the S39 Ignition Switch (or S38 Ignition Mode Switch) is in any position other than OFF. The object high speed GMLAN serial data bus uses terminating resistors that are in parallel with the object high speed GMLAN (+) and (-) circuits.