Buick Network Map

Buick follows GM corporate network architecture and GMLAN protocols shared with other GM brands of the same era. Vehicles transitioned to a dual-bus GMLAN architecture around 2004: a high-speed bus (500 kb/s) on DLC pins 6/14 for powertrain and chassis, and a low-speed GMLAN (33.3 kb/s) for body and convenience functions accessed through a gateway. The Body Control Module (BCM) serves as the gateway between buses. Pre-2004 vehicles used GM Class 2 (J1850 VPW) on DLC pin 2. On later models GM introduced a Security Gateway that requires authentication for module reprogramming and blocks certain aftermarket scan functions.

Testing values and scope patterns are universal — they live on the main CAN playbook. This page is what's specific to Buick: the buses, where the terminators live, and what breaks. Tap any era to explore it — network map, testing guide, failure patterns.