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. 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 Communication Schematics

Audio Amplifier

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Automatic Occupant Sensing (PPS)

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Body Control Module (BCM)

    • High Speed GMLAN
    • Low Speed GMLAN

Scan Tool Does Not Communicate with High Speed GMLAN Device

Digital Radio Receiver (DRR)

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Driver Door Module (DDM)

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Driver Position Module (MSM)

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Electronic Brake Control Module (EBCM)

High Speed GMLAN

Scan Tool Does Not Communicate with High Speed GMLAN Device

Electronic Suspension Control (ESC or MRRTD) Module

High Speed GMLAN

Scan Tool Does Not Communicate with High Speed GMLAN Device

Engine / Powertrain Control Module (ECM/PCM)

High Speed GMLAN

Scan Tool Does Not Communicate with High Speed GMLAN Device

Export Body Control Module (XBCM)

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Headlamp Leveling Control Module (HCM) w/ TR7

Keyword 2000

Dedicated data line from terminal 7 of the DLC to the HCM

Heated Seat Module (HSM)

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

HVAC Control Module

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Instrument Panel Cluster (IPC)

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Inflatable Restraint Sensing and Diagnostic Module (SDM)

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Passenger Door Module (PDM)

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Power Liftgate Module (PLGM)

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Radio

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Rear Seat Audio (RSA) Module

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Rear Seat Module (RSM)

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Remote Control Door Lock Receiver (RCDLR)

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Rollover Sensor (ROS)

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Theft Deterrent Module (TDM)

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Transmission Control Module (TCM)

High Speed GMLAN

Scan Tool Does Not Communicate with High Speed GMLAN Device

Universal Park Assist (UPA) Module

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Vehicle Communication Interface Module (OnStar VCIM)

    • High Speed GMLAN - pass through only
    • Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device