Body Computer Module: Description

CAUTION: When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery.

CAUTION: Power should never be removed or applied to ECM or BCM with ignition switch turned to ON position. Before removing or connecting battery cables, fuses, or ECM/BCM connectors, always turn ignition switch to OFF position to prevent damage to modules.

Cadillac Allante uses several components that can be controlled to provide self-diagnostic information. These components are part of an electrical network that is Designed to control various engine and body subsystems.

At the heart of the computer system is the Body Control Module (BCM). The BCM is located behind the center "Heater/Air Conditioning" vents on the dashboard. The BCM has an integral microprocessor, which is the center for communication with all the other components in the system.

The distributed lighting monitoring system consists of 9 Output Switching Modules (OSM's No. 2 through No. 10), the BCM, and the lighting control panel or Left Switch Pod (LSP). All the components communicate through a data circuit that is controlled by the BCM.

The BCM acts as a back-up system to control 2 redundant relays to allow for essential lighting in case of a major fault in the system.