Circuit Description
WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
The electronic brake control module (EBCM) learns the model options that it is installed in by using the Vehicle ID information from the body control module (BCM) via the class 2 serial data line. Each time the vehicle is in the RUN position the BCM communicates this information via class 2. The EBCM internally compares the VIN and option information with that information stored in the BCM.