Circuit Operation

The Data Link Connector (DLC) contains:
^ The UART serial data line (circuit 800) which allows the Powertrain Control Module (PCM), the Sensing and Diagnostic Module (SDM), and Electronic Brake Control Module (EBCM) to communicate data with each other. In addition, the UART serial data line allows a scan tool to communicate with these modules for diagnostic and testing purposes.
^ The Class 2 serial data line (circuit 1807) which allows a scan tool to communicate with the PCM for diagnostic and testing purposes.
^ Unswitched voltage (B+) (circuit 640).
^ Ground (circuit 1550).
^ The theft deterrent module test light output (circuit 728) on SEO equipped vehicles which allows either a test light or a scan tool to monitor the status of the theft deterrent module for diagnostic purposes.