Class 2 Serial Data Line

The class 2 serial data line on this vehicle is a star configuration. The powertrain control module (PCM) has an additional class 2 serial data circuit to body control module (BCM) or to theft deterrent control module, if equipped. If one of the class 2 serial data circuits to the PCM opens, communication will not be interrupted. The following modules communicate on the class 2 serial data line:

• The audio amplifier (early production) - refer to Radio/Audio System Description and Operation in Entertainment for more information.
• The body control module (BCM)
• The digital radio receiver (DRR)
• The driver door module (DDM)
• The driver seat module (DSM)
• The electronic brake control module (EBCM)
• The electronic control suspension (ESC) module
• The front passenger door control module (FPDM)
• The HVAC control module
• The HVAC control module - rear auxiliary
• The inflatable restraint sensing and diagnostic module (SDM)
• The instrument panel cluster (IPC)
• The powertrain control module (PCM)
• The radio
• The rear seat audio (RSA) controller
• The rear seat entertainment (RSE) assembly, w/U42
• The rear wheel steering control module (RWSCM)
• The remote playback device - CD player, (CDX) w/U1S
• The theft deterrent control module (VTD), for export
• The transfer case shift control module (TCSCM), w/4WD
• The vehicle communication interface module (VCIM), w/UE1

The class 2 serial data line allows a scan tool to communicate with these modules for testing purposes, checking for DTCs, and to activate/enable/disable functions. These class 2 serial data circuits are bussed together via 2 splice packs and a DLC:

• SP205-Located behind the I/P near the headlamp switch connector.
• SP206-Located in the I/P harness near the left B pillar.
• SP207-Located in the I/P harness.
• DLC-Connects the scan tool to the class 2 serial data circuits.

Refer to Data Link Communications Component Views .