Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Body Control Module
Body Control Module (BCM) is capable of accomplishing multiple body control functions. Components directly connected to BCM are controlled by BCM outputs. BCM controls outputs based on input information it obtains from sensors and switches that are directly connected to BCM, or by receiving information from other vehicle systems connected to class 2 serial data circuit. BCM evaluates this information and controls certain body systems by commanding an output on or off.
BCM is also capable of commanding other vehicle systems to control functions that are not directly wired to and/or controlled by BCM. BCM accomplishes this task by sending specific messages on class 2 serial data circuit. Vehicle system capable of performing such function will respond to BCM message.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.