WHAT IS BODY CONTROL MODULE (BCM)?
The Body Control Module (BCM), which is the heart of the vehicle electrical architecture, integrates a fused electrical bus center for power distribution and a body computer in a single module. This integration concept is designed to streamline and optimize wiring and wiring connections by removing redundant power feeds, increase the sharing of fusing, and to fully utilize the capability of electronics and module foundation by including multiple functions within the same housing thereby re-using microcontroller, power supply, transient protections, housing, brackets, etc.
The BCM contains the following main parts:
Electronic Body Function Controller - Many of the body and light functions are controlled by the BCM.
Switching and Fuse Block - The BCM will handle fusing and switching of loads in the vehicle. Electromechanical relays or power MOSFETs are used for the switching.
Electrical Junction and Distribution Block - The BCM acts as a connection block between several cable harnesses. It is also the source of the different voltages used in the electrical distribution system, based upon Power Mode. The sequencing of voltages at start-up and shut down is controlled by the BCM.
The BCM module contains one six layer,1oz copper, FR4 Board PCB enclosed in a single plastic housing, PCB mounted relays as well as fuse forks to interface with the Serviceable fuses and circuit breaker, Power Supply, Microcontrollers, Communication ICs, Power Drivers, and interface circuits for analog and digital inputs. All variants of the BCM share common PCB. The population of the electronics components on the PCBs is variant dependent. There is one power feed to this module. The BCM has a Logic Ground and Power Ground, which is used for the GND reference for the Door Locking H-Bridge Outputs. The module communicates with the other vehicle electronic devices via high speed CAN, 4 LIN Channels. In addition, the module controls and processes several digital and analog inputs and outputs.
Source: https://fcc.report/FCC-ID/M3N74295202/2212791.pdf
https://en.wikipedia.org/wiki/Electronic_control_unit