Data Link Connector (DLC)
The DLC is a standardized 16-way connector located below the instrument
panel and close to the steering column. Both the connector design and location
are dictated by industry wide agreements. All DLCs are required to provide
a power supply, B+ at all times, to Pin 16. This positive supply is used
to power the scan tool. All DLCs supply a power ground at Pin 4 and a clean
signal ground at Pin 5. The class 2 serial data circuit is provided
at pin 2 of the DLC.
Optional Serial Data Gateway
The optional serial data gateway is translation node that converts class 2
serial data protocol to controller area network (CAN) protocol and CAN to
class 2 serial data protocol. The vehicle powertrain options determine
if this gateway is installed on the vehicle or not. The EBCM, PCM and TCM
options that communicate over CAN use the SDGM to communicate
with other modules on the class 2 serial data bus, but communicate
between themselves on the CAN bus.
Class 2 Serial Data Link
The class 2 serial data link in this vehicle is configured in a star
which means, there is no redundant path for the serial data to flow through,
in the event that the conductor feeding a module develops an open condition
that module will not be able to communicate. The following modules use
the data link network to communicate with each other:
| • | The electronic brake control module (EBCM) |
| • | The powertrain control module (PCM) |
| • | The inflatable restraint sensing and diagnostic module (SDM) |
| • | The transmission control module (TCM) |
| • | The serial data gateway module (SDGM) |
| • | The multifunction alarm module/chime module (MAM) |
| • | The instrument panel cluster (IPC) |
| • | The remote control door lock receiver (RCDLR) |
The class 2 serial data link allows a scan tool to communicate
with the above modules for diagnostic and testing purposes.
