Circuit Description
WARNING: This page is about a different car, the 2005 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.
When a cruise control function switch is activated, the body control module (BCM) detects a predetermined voltage signal. The BCM sends a GMLAN serial data message to the powertrain control module (PCM) indicating the function that has been requested.