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. This table is used to assist in correcting a communication malfunction between the control module and 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 (AMP), w/UQ7 and Y91

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Body Control Module (BCM)

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Communication Interface Module (OnStar®), w/UE1

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Digital Radio Receiver (DRR), w/U2K

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Driver Door Module (DDM)

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Electro-Hydraulic Power Steering (EHPS) Module, w/HP2

High Speed GMLAN

Scan Tool Does Not Communicate with High Speed GMLAN Device

Electronic Brake Control Module (EBCM)

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Energy Storage Control Module (ESCM), w/HP2

High Speed GMLAN

Scan Tool Does Not Communicate with High Speed GMLAN Device

Engine Control Module (ECM), w/LLY

    • High Speed GMLAN
    • Class 2

Scan Tool Does Not Communicate with Class 2 Device

Generator Battery Control Module (GBCM)

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Glow Plug Control Module (GPCM) w/LLY

High Speed GMLAN

Scan Tool Does Not Communicate with High Speed GMLAN Device

HVAC Control Module

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Hybrid Control Module (HCM), w/HP2

    • High Speed GMLAN
    • Class 2

Scan Tool Does Not Communicate with Class 2 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), w/AN3

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Passenger Door Module (PDM)

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Powertrain Control Module (PCM)

    • High Speed GMLAN, w/HP2
    • Class 2

Scan Tool Does Not Communicate with High Speed GMLAN Device

or

Scan Tool Does Not Communicate with Class 2 Device

Radio

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Rear Seat Audio (RSA) Controller, w/UK6

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Rear Seat Entertainment (RSE), w/U42

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Rear Wheel Steering Control Module (RWSCM), w/NYS

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Remote Playback Device - CD Player (CDX), w/U1S

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Starter/Generator Control Module (SGCM), w/HP2

High Speed GMLAN

Scan Tool Does Not Communicate with High Speed GMLAN Device

Transfer Case Shift Control Module (TCSCM), w/NP1, NP8

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Transmission Control Module (TCM), w/M74

    • High Speed GMLAN, w/LLY
    • Class 2

Scan Tool Does Not Communicate with High Speed GMLAN Device

or

Scan Tool Does Not Communicate with Class 2 Device