GM Service Manual Online
For 1990-2009 cars only

This table identifies which serial data link that a particular module uses for in-vehicle data transmission. Some modules may use more than one data link to communicate. Some modules may have multiple communication circuits passing through them without actively communicating on that data link. This table is used to assist in correcting a communication malfunction with the scan tool. For the description and operation of these serial data communication circuits, refer to Data Link Communications Description and Operation .

Control Module

Data Link Type

Diagnostic Procedure

Schematic Reference: Data Link Connector Schematics

Audio Amplifier (Bose)

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Auxiliary Gage Center, w/ERG or ERH

Class 2

This module doesn't communicate with the scan tool.

Body Control Module (BCM)

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Electronic Brake Control Module (EBCM)

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Engine Control Module (ECM)

    • High Speed GMLAN
    • Class 2

Scan Tool Does Not Communicate with High Speed GMLAN Device

Inflatable Restraint Sensing and Diagnostic Module (SDM)

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Instrument Panel Cluster (IPC)

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Memory Seat Module (MSM) - Driver, w/AAB

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Roof/Door Module (RDM)

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Radio

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Remote Control Door Lock Receiver (RCDLR)

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Transmission Control Module (TCM), w/M32

    • High Speed GMLAN
    • Class 2

Scan Tool Does Not Communicate with High Speed GMLAN Device