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 Body Control System Description and Operation.

Control Module

Data Link Type

Diagnostic Procedure

Schematic Reference: Body Control System Description and Operation

Active Front Steering (AFS) Module w/ JL7

High Speed GMLAN

Scan Tool Does Not Communicate with High Speed GMLAN Device

Audio Amplifier

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Vehicle Communication Interface Module (OnStar)

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

Scan Tool Does Not Communicate with High Speed GMLAN Device Scan Tool Does Not Communicate with Low Speed GMLAN Device

Digital Radio Receiver (DRR) Module

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Distance Sensing Cruise Control (DSCC) Module

High Speed GMLAN

Scan Tool Does Not Communicate with High Speed GMLAN Device

Driver Door Module (DDM)

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Driver Door Switch (DDS)

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Dynamic Headlamp Leveling (DHL) Module, w/ TR7

High Speed GMLAN

Scan Tool Does Not Communicate with High Speed GMLAN Device

Driver Position (Memory Seat) Module

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 Control Module (ECM)

High Speed GMLAN

Scan Tool Does Not Communicate with High Speed GMLAN Device

Head Up Display (HUD)

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Climate Control Panel (CCP) 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

Instrument Panel Module (IPM)

    • High Speed GMLAN
    • Low Speed GMLAN

Scan Tool Does Not Communicate with High Speed GMLAN Device 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

Left Rear Door Module (LRDM)

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

Radio

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Rear Integration Module (RIM)

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

Right Rear Door Module (RRDM)

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Side Blind Zone Alert (SBZA) Module, left

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Side Blind Zone Alert (SBZA) Module, right

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Steering Column Lock Control Module (SCLM), w/ UA2

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device

Supervisory Control Module (SCM) w/ JL7

High Speed GMLAN

Scan Tool Does Not Communicate with High Speed GMLAN Device

Television Tuner Module, w/ YQ6 or YQ7

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

Vehicle Direction Alert Alarm (Lane Departure) Warning Module

Low Speed GMLAN

Scan Tool Does Not Communicate with Low Speed GMLAN Device