Information Bus: Description and Operation

There are two data lines that can be accessed with a scan tool. The 461 circuit data line is the ECM Data Line. It allows the Electronic Control Module, Driver Information Center/Electronic Compass and Electronic Brake Control Module (EBCM) (if equipped) to communicate by transmitting data through the ORN (461) wire. The 835 circuit data line is the Entertainment and Comfort (E&C Bus) Data Line. It allows the Radio and Radio Control Interface Module to communicate via the DK GRN (835) wire.
A scan tool can be connected to the ALDL Connector, this allows the scan tool to communicate with both the ECM Data Line and E&C Data Lines. System operations can then be monitored for diagnostic purposes.