Class 2 Circuit Description
WARNING: This page is about a different car, the 2008 Chevrolet HHR. However, it is still accessible from the selected car via links, so may be relevant.
The data link connector (DLC) allows a scan tool to communicate with the class 2 serial data circuit. Class 2 serial data is transmitted on a single wire at an average of 10.4 Kbps. The bus is active at 7 volts nominal and inactive at ground potential. When the ignition switch is in RUN, and a scan tool is connected to the DLC, the powertrain control module (PCM) will start communicating diagnostic information over the class 2 serial data circuit.