GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2009 🢒 TrailBlazer - 4WD 🢒 Power and Signal Distribution 🢒 Data Communications 🢒 Data Link References

Diagnostic Aids

The air suspension control module does not communicate on any data link. For additional information refer to Diagnostic Trouble Code (DTC) Displaying.

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

Body Control Module (BCM)

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Digital Radio Receiver (DRR)

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

Driver Seat Module (DSM)

Class 2

Scan Tool Does Not Communicate with Class 2 Device

DVD Player

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) w/ 5.3L engine
    • High Speed GMLAN
    • Class 2

Scan Tool Does Not Communicate with High Speed GMLAN Device

HVAC Control Module

Class 2

Scan Tool Does Not Communicate with Class 2 Device

HVAC Control Module - Rear Auxiliary

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

Liftgate Module (LGM)

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), w/ 4.2L engine

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Radio

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Regulated Voltage Control Module (battery current sensor)

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Theft Deterrent Module (TDM)

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Transfer Case Control Module (TCCM)

Class 2

Scan Tool Does Not Communicate with Class 2 Device

Transmission Control Module (TCM)

High Speed GMLAN

Scan Tool Does Not Communicate with High Speed GMLAN Device

Vehicle Communication Interface Module (OnStar® VCIM)

Class 2

Scan Tool Does Not Communicate with Class 2 Device