Uart Operation

The UART Data Line lets different controllers in the vehicle to communicate or "talk" using serial data. The UART Data Line allows the Instrument Panel Cluster IPC, TECH 2 Scan Tool (when connected), Sensing Diagnostic Module (SDM), Powertrain Control Module (PCM), and the Electronic Brake Control Module (EBCM) to communicate over a single wire.

During normal operation the IPC polls (talks to) each of the modules on the UART Data Line (5DM, EBCM, and PCM). As each module is polled, it is in turn prompted to send a return message containing sensor and diagnostic related data. The IPC collects and divides up all of the serial data on the UART Data Line and sends it to the appropriate module when it polls that module. The IPC is called the master of the UART Line, where the others are "slaves". The IPC receives most telltale and gage information in this fashion.