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