Key Considerations for Reliable Performance

Automotive body control modules (BCMs) manage a range of features designed to enhance driver safety. As driving and environmental conditions change, wipers, interior and exterior lighting, mirrors, locks, thermostats, and windows need to keep pace with the operator’s commands. 

How does a body control module work?

Like the name implies, the body control module is the centralized hub for managing several systems necessary for the vehicle's safe operation.   

Sensors and switches provide the inputs processed within the microcontroller unit (MCU). The MCU then signals and controls the load drivers that empower the output devices to execute the desired actions. 

A CAN/LIN bus manages the connectivity as analog and digital inputs are processed via the interface and MCU. The MCU also directs lighting systems for status indication and other driver communication methods. 

In some cases, the BCM is connected to the instrument cluster or other internal systems. By communicating with other onboard computers and systems, the BCM enables multiple functions within the vehicle without requiring additional wiring for each one. 

BCM Block Diagram

Engineering & Design Considerations

• Safety - because the BCM manages several functions essential to the safe operation of the vehicle, unreliable components aren’t an option
• Processing speed & response times - although multiple ECUs and systems must communicate and be processed in the BCM, these events need to happen in real time, so speed is crucial 
• Reverse battery protection - protective diodes should be included to prevent damaging reverse voltage in the battery
• Overvoltage protection - transients and power surges do happen in auto applications, so the body control module parts should incorporate those into the design
• Efficiency - powered by the vehicle’s battery, which also powers all other electrical systems, the BCM should operate as efficiently as possible

• ESD protection - electrostatic discharge can impact the reliability of the BCM and its components, so protection measures must be in place
• Applicable industry standards - all components must adhere to strict automotive industry guidelines, including AEC-Q101

Recommended Products