Body Control Module: Description and Operation

The Body Computer Module (BCM) is the heart of the computer network. The BCM has an internal microprocessor and uses a single data line to communicate with all the other components, and also controls the on-board diagnostics of the vehicle. The data communication gives the BCM control over the Powertrain/Electronic Control Module's (PCM/ECM's) self diagnostic capabilities in addition to its own. The BCM controls body sub-systems such as cooling fan control, fuel data display, outside temperature display, rear defogger, retained accessory power, self-diagnostics, and vacuum fluorescent display dimming. In order to access and control the BCM self-diagnostic features, the Instrument Panel Cluster (IPC) and Climate Control Driver Information Center (CCDIC) are used.