Circuit Operation
There are two
data lines that can be accessed with a scan tool. The UART data line (800 CKT) allows the scan tool (when connected),
Powertrain Control Module,
(PCM) Instrument Cluster
(I/P), Diagnostic Energy Reserve Module
(DERM), and the Electronic Brake Control Module
(EBCM) to communicate via
serial data. The OBDII data line (1807 CKT) allows a scan tool to directly access the Powertrain Control Module to read emissions related information. A scan tool can gain access to both data lines through the Data Link Connector
(DLC). System operations can then be monitored or controlled for diagnostic purposes.