Class 2 Serial Data Usage
WARNING: This page is about a different car, the 2005 Pontiac Pursuit and 2005 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
The class 2 serial data communications circuit on this vehicle is only used for powertrain control module (PCM) diagnostics and PCM service programming system (SPS) programming.