Data Link References

WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

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)	High Speed GMLAN Low Speed GMLAN	Scan Tool Does Not Communicate with High Speed GMLAN Device
Communication Interface Module (OnStar), w/UE1	High Speed GMLAN - pass through only Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device
Chime Module w/UL5	Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device
Digital Radio Receiver (DRR), w/U2K	Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device
Driver Door Switch (DDS)	Low Speed GMLAN Local Interconnect Network (LIN)	Scan Tool Does Not Communicate with Low Speed GMLAN Device
Electronic Brake Control Module (EBCM)	High Speed GMLAN	Scan Tool Does Not Communicate with High Speed GMLAN Device
Electronic Suspension Control Module (ESCM), F45, F55	High Speed GMLAN	Scan Tool Does Not Communicate with High Speed GMLAN Device
Engine/Powertrain Control Module (ECM/PCM)	High Speed GMLAN	Scan Tool Does Not Communicate with High Speed GMLAN Device
Front and Rear Object Alarm Module	Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device
Fuel Pump Control Module (FPCM)	High Speed GMLAN	Scan Tool Does Not Communicate with High Speed GMLAN Device
Glow Plug Control Module (GPCM)	High Speed GMLAN	Scan Tool Does Not Communicate with High Speed GMLAN Device
HVAC Control Module	Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device
Inside Rearview Mirror	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
Inflatable Restraint Sensing and Diagnostic Module (SDM)	Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device
Inflatable Restraint Roll Over Sensor (ROS) w/ASF	Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device
Memory Seat Module (MSM)/Driver Position Module (DPM)	Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device
Passenger Door Switch (PDS)	Low Speed GMLAN Local Interconnect Network (LIN)	Scan Tool Does Not Communicate with Low Speed GMLAN Device
Passenger Presence System (PPS)	Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device
Power Take Off Module (PTO)	High Speed GMLAN	Scan Tool Does Not Communicate with High Speed GMLAN Device
Radio	Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device
Rear Seat Audio (RSA) w/UK6	Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device
Remote Control Door Lock Receiver (RCDLR) w/AP3, AP8	Low Speed GMLAN	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 (TBCM)	High Speed GMLAN	Scan Tool Does Not Communicate with High Speed GMLAN Device
Transfer Case Control Module (TCCM) w/NP8, NR3, NQH, NQF, NGQ	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
Ultrasonic Parking Aid (UPA) Module w/UD7	Low Speed GMLAN	Scan Tool Does Not Communicate with Low Speed GMLAN Device