GM Service Manual Online
For 1990-2009 cars only

The serial data line is the means by which the microprocessor controlled modules in the vehicle communicate with other control modules and the scan tool.

The control modules on the class 2 data line are as follows:

    • Body control module (BCM)
    • Instrument cluster (IPC)
    • Automatic transfer case (ATC) control module
    • Vehicle control module (VCM)
    • Powertrain control module (PCM)
    • Inflatable restraint sensing and diagnostic module (SDM)
    • Electronic Brake Control Module (EBCM)
    • Suspension Control Module (SCM)
    • HVAC Control Module