Data Link References

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
Accessory DC Power Control Module w/ HP2	Powertrain High Speed GMLAN	Scan Tool Does Not Communicate with Powertrain High Speed GMLAN Device
AC Compressor w/ HP2	Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device
Assist Step Control Module	Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device
Audio Amplifier	Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device
Body Control Module (BCM)	High Speed GMLAN Low Speed GMLAN Local Interconnect Network (LIN)	Scan Tool Does Not Communicate with High Speed GMLAN Device Scan Tool Does Not Communicate with Low Speed GMLAN Device DTC U1500, U1511, U1512, or U1513
Digital Radio Receiver	Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device
Drive Motor Generator Battery Control Module w/ HP2	High Speed GMLAN	Scan Tool Does Not Communicate with High Speed GMLAN Device
Drive Motor Generator Power Inverter Module w/ HP2	Powertrain High Speed GMLAN High Speed GMLAN	Scan Tool Does Not Communicate with Powertrain High Speed GMLAN Device Scan Tool Does Not Communicate with High Speed GMLAN Device
Door Lock/Window Switch- Driver	Low Speed GMLAN Local Interconnect Network (LIN)	Scan Tool Does Not Communicate with Low Speed GMLAN Device DTC U1500, U1511, U1512, or U1513
Door Lock/Window Switch- Passenger	Low Speed GMLAN Local Interconnect Network (LIN)	Scan Tool Does Not Communicate with Low Speed GMLAN Device DTC U1500, U1511, U1512, or U1513
Electronic Brake Control Module (EBCM)	High Speed GMLAN Powertrain High Speed GMLAN	Scan Tool Does Not Communicate with High Speed GMLAN Device Scan Tool Does Not Communicate with Powertrain High Speed GMLAN Device
Electronic Compass Module	Local Interconnect Network (LIN)	DTC U1500, U1511, U1512, or U1513
Electronic Power Steering Motor Control Module w/ HP2	High Speed GMLAN	Scan Tool Does Not Communicate with High Speed GMLAN Device
Electronic Suspension Control (ESC) Module	High Speed GMLAN	Scan Tool Does Not Communicate with High Speed GMLAN Device
Engine / Powertrain Control Module (ECM/PCM)	High Speed GMLAN Powertrain High Speed GMLAN	Scan Tool Does Not Communicate with High Speed GMLAN Device Scan Tool Does Not Communicate with Powertrain High Speed GMLAN Device
Fuel Pump Flow Control Module	High Speed GMLAN	Scan Tool Does Not Communicate with High Speed GMLAN Device
Heated Seat Module- Rear	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
Inflatable Restraint Sensing and Diagnostic Module (SDM)	Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device
Inflatable Restraint Vehicle Rollover Sensor	Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device
Inside Rearview Mirror (ISRVM)	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
Memory Seat Module (MSM)	Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device
Object Alarm Module	Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device
Passenger Presence System (PPS) Module	Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device
Power Liftgate Module	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) Control	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
Serial Data Gateway Module (SDGM) w/ HP2	Powertrain High Speed GMLAN High Speed GMLAN Low Speed GMLAN	Scan Tool Does Not Communicate with Powertrain High Speed GMLAN Device Scan Tool Does Not Communicate with High Speed GMLAN Device 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
Trailer Brake Control Module	High Speed GMLAN	Scan Tool Does Not Communicate with High Speed GMLAN Device
Transfer Case Shift Control Module	High Speed GMLAN	Scan Tool Does Not Communicate with High Speed GMLAN Device
Transmission Control Module (TCM)	High Speed GMLAN	Scan Tool Does Not Communicate with High Speed GMLAN Device
Vehicle Communication Interface Module (OnStar® VCIM)	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
Window Motor- Driver	Local Interconnect Network (LIN)	DTC U1500, U1511, U1512, or U1513
Window Motor- Passenger	Local Interconnect Network (LIN)	DTC U1500, U1511, U1512, or U1513
Yaw and Lateral Accelerometer Sensor w/ HP2	Powertrain High Speed GMLAN	Scan Tool Does Not Communicate with Powertrain High Speed GMLAN Device