Class 2 Serial Data Link

The data link is a ring/star configuration with discrete lines entering and leaving each module. This allows communications to the modules on the ring if one of the two discrete circuits is open.

A total list of the control modules on the Class 2 Serial Data Line can include the following:
^ Cellular Telephone Module
^ Dash Integration Module (DIM)
^ Driver Door Module (DDM)
^ Driver Door Switch Assembly (DDSA)
^ Electronic Brake Control Module (EBCM)
^ Electronic Suspension Control Module
^ Inflatable Restraint Sensing and Diagnostic Module (SDM)
^ Instrument Cluster
^ Instrument Panel Integration Module (IPM)
^ LH Middle Door Module (LMDM)
^ LH Rear Door Module (RRDM)
^ Memory Seat Module (MSM) with A45
^ Navigation Data Entry Processor
^ Navigation Data Processor
^ Passenger Door Module (PDM)
^ Powertrain Control Module (PCM)
^ Radio
^ Radio Amplifier (AMP)
^ Rear Heater and NC Control (RCC)
^ Rear Integration Module (RIM)
^ Remote Function Actuator (RFA)
^ RH Front Door Power Window Switch (PDS) (if equipped W/armored car)
^ RH Middle Door Module (RMDM)
^ RH Rear Door Module (RRDM)
^ Steering Column Module
^ Theft Deterrent Module
^ Vehicle Interface Unit (VIU)

The following modules have only one communication line connection to the Class 2 data circuit:
^ Cellular Telephone Module
^ Driver Door Module (DDM)
^ Driver Door Switch Assembly (DDSA)
^ Electronic Suspension Control Module
^ LH Middle Door Module (LMDM)
^ LH Rear Door Module (LRDM)
^ Memory Seat Module (MSM)
^ Navigation Data Processor
^ Passenger Door Module (PDM)
^ Radio (W/UY4)
^ Radio Amplifier (AMP)
^ Rear Heater and NC Control
^ Rear Integration Module (RIM)
^ Remote Function Actuator (RFA)
^ RH Front Power Window Switch (PDS) (if equipped W/armored car)
^ RH Middle Door Module (RMDM)
^ RH Rear Door Module (RRDM)
^ Steering Column Module
^ Theft Deterrent Module
^ Vehicle Interface Unit (VIU)

For a description of the RPO Code(s) shown in this image/article refer to the RPO Code List found at Vehicle/Application ID Application and ID