Circuit/System Description
WARNING: This page is about a different car, the 2022 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.
The Electronic Brake Control Module/Brake System Control Module contains the logic for the parking brake function. The EBCM/BSCM sends out a EPB availability and application status signal on the high speed GMLAN which is monitored by the Engine Control Module. The ECM uses this information for certain functions associated with the Electronic Transmission Range Selector. The ECM needs to verify that EPB functionality is available for ETRS Critical Fault Mode or Latent Fault Mode.