Data Link References

This table identifies which serial data link that a particular device uses for in-vehicle data transmission. Some devices may use more than one data link to communicate. Some devices 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. Not all devices listed will be applicable to all vehicles. Refer to the schematics to determine which devices apply. For the description and operation of these serial data communication circuits, refer to Data Link Communications Description and Operation .

Code	Device	Data Link Type	Diagnostic Procedure
Schematic Reference: Data Communication Schematics
A11	Radio	Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device
A26	HVAC Controls	Local Interconnect Network (LIN)	DTC U1500-U15FF
B99	Steering Wheel Angle Sensor	Chassis High Speed GMLAN	Scan Tool Does Not Communicate with Chassis High Speed GMLAN Device
K9	Body Control Module	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-U15FF
K17	Electronic Brake Control Module	High Speed GMLAN Chassis High Speed GMLAN	Scan Tool Does Not Communicate with High Speed GMLAN Device Scan Tool Does Not Communicate with Chassis High Speed GMLAN Device
K20	Engine Control Module	High Speed GMLAN Powertrain Expansion Bus	Scan Tool Does Not Communicate with High Speed GMLAN Device DTC U0074 (Chassis Expansion Bus) DTC U0074 (Powertrain Expansion Bus)
K33	HVAC Control Module	Low Speed GMLAN Local Interconnect Network (LIN)	Scan Tool Does Not Communicate with Low Speed GMLAN Device DTC U1500-U15FF
K36	Inflatable Restraint Sensing and Diagnostic Module	Low Speed GMLAN Chassis High Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device Scan Tool Does Not Communicate with Chassis High Speed GMLAN Device
K38	Chassis Control Module	High Speed GMLAN	Scan Tool Does Not Communicate with High Speed GMLAN Device
K43	Power Steering Control Module	High Speed GMLAN Chassis High Speed GMLAN	Scan Tool Does Not Communicate with High Speed GMLAN Device Scan Tool Does Not Communicate with Chassis High Speed GMLAN Device
K71 / Q8	Transmission Control Module / Control Solenoid Valve Assembly	High Speed GMLAN	Scan Tool Does Not Communicate with High Speed GMLAN Device
K85	Passenger Presence Module	Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device
K89	Immobilizer Control Module	Local Interconnect Network (LIN)	DTC U1500-U15FF
K111	Fuel Pump Driver Control Module	Powertrain Expansion Bus	DTC U0074 (Chassis Expansion Bus) DTC U0074 (Powertrain Expansion Bus)
P16	Instrument Cluster	Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device
S79D	Window Switch - Driver	Local Interconnect Network (LIN)	DTC U1500-U15FF
S79LR	Window Switch - Left Rear	Local Interconnect Network (LIN)	DTC U1500-U15FF
S79P	Window Switch - Passenger	Local Interconnect Network (LIN)	DTC U1500-U15FF
S79RR	Window Switch - Right Rear	Local Interconnect Network (LIN)	DTC U1500-U15FF