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 agreement to follow SAE J1962 standards.
All DLCs are required to provide a power supply, hot at all times, to
Pin 16. This circuit 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.
The microprocessor-controlled modules in the vehicle communicate with
each other through the serial data lines. This vehicle uses 2 serial
data lines:
| • | The Entertainment and Comfort serial data line |
| • | The Class 2 serial data line |
Entertainment and Comfort Serial Data Line
The Entertainment and Comfort serial data line is an arbitrated communications
system similar to class 2. The control modules on the Entertainment
and Comfort serial data line can include the following modules:
| • | Remote playback device - (CD) changer |
The Entertainment and Comfort serial data line is not connected to the
data link connector (DLC), so it can not be accessed with a scan tool. The
Entertainment and Comfort serial data line is diagnosed in the Entertainment
section. Refer to
Diagnostic System Check - Radio/Audio System
in Entertainment.
Class 2 Data Line
The data link is a ring/star configuration with discrete lines entering
and leaving each module. This allows communications to the modules on the
ring if one of the two discrete circuits is open.
A total list of the control modules on the Class 2 Serial Data
Circuit can include the following:
| • | Body control module (BCM) |
| • | Continuously variable road sensing suspension (CVRSS) module w/F45 |
| • | Electronic brake control module (EBCM) |
| • | Inflatable restraint sensing and diagnostic module (SDM) |
| • | Instrument panel cluster (IPC) |
| • | Memory mirror module (MMM) w/A45 |
| • | Memory seat module (MSM) w/A45 |
| • | Powertrain control module (PCM) |
| • | Radio interface module (RIM) w/UQ4 |
| • | Remote control door lock receiver (RCDLR) |
| • | Vehicle interface unit (VIU) |
The VIU has only one communication line connection to the Class 2
serial data circuit.
