BCM Overview
The main features of the body control module (BCM) are:
| • | The BCM is the gateway between the on class 2 serial data circuit and controller area network (CAN) serial data circuit. |
| • | The BCM controls multiple functions. |
| • | The BCM is the power mode master. |
Gateway
The body control module (BCM) communicates functionally on both class 2 and controller area network (CAN) serial data buses. The BCM is the gateway between the buses and transfers serial data messages from one subnet to another. Diagnostic communication
of the BCM with the scan tool is through class 2 serial data circuit.
BCM Functions
The body control module (BCM) performs multiple body control functions. The BCM can control devices directly connected to its outputs based on input information. The BCM evaluates this information and controls certain body control systems by commanding
outputs on or off. The BCM inputs can be:
| • | Sensors and switches that are directly connected to the BCM |
| • | Class 2 serial data messages received from other vehicle systems connected to the class 2 serial data link |
| • | Controller area network (CAN) serial data messages received from other vehicles systems connected to the CAN serial data link |
The BCM is also capable of controlling other vehicle systems that are not directly wired to the BCM. The BCM does this by sending specific messages on the class 2 serial data link or CAN serial data link. The system capable of performing the required
function will respond to the BCM messages.
Some of the other systems functions that BCM controls or contributes to are:
Power Mode
The BCM is the power mode master (PMM). Refer to
Power Mode Description and Operation for more information.
