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
The various body control module (BCM) input and output circuits are described in the corresponding functional areas indicated on the BCM electrical schematics. The BCM functions include the following:
- Battery rundown protection (inadvertent power)-Refer to Interior Lighting Systems Description and Operation .
- Bulb check-Refer to Instrument Cluster Description and Operation .
- Chimes-Refer to Indicator/Warning Message Description and Operation
.
- Check gauges
- Door ajar warning
- Headlamps ON
- Key-in-ignition
- Oil reset
- Park brake warning
- Seat belt not fastened
- Turn signal ON
- Door lock interface-Refer to Power Door Locks Description and Operation .
- Electronic power steering (EPS)-Refer to Power Steering System Description and Operation .
- Engine coolant level sensing-Refer to Cooling System Description and Operation .
- Exterior and interior lighting control-Refer to Exterior Lighting Systems Description and Operation
.
- Automatic lighting control
- Daytime running lamps (DRL)
- Fog lamps
- Park brake lights
- Turn hazard lamps
- Gauge control-Refer to Instrument Cluster Description and Operation .
- Horn interface-Refer to Horns System Description and Operation .
- HVAC-Refer to Manual HVAC Description and Operation .
- Instrument cluster indicator control-Refer to Instrument Cluster Description and Operation .
- Interior lighting-Refer to Interior Lighting Systems Description and Operation .
- Key-in-ignition sensing-Refer to Indicator/Warning Message Description and Operation .
- Parking brake state sensing-Refer to Brake Warning System Description and Operation .
- Retained accessory power (RAP)-Refer to Retained Accessory Power Description and Operation .
- Rear compartment interface-Refer to Power Door Locks Description and Operation .
- Rear defogger-Refer to Rear Window Defogger Description and Operation .
- Remote function control-Refer to Keyless Entry System Description and Operation (without Accessory 2 Way Remote) or Keyless Entry System Description and Operation (with Accessory 2 Way Remote) .
- Seat belt use sensing-Refer to Seat Belt System Description and Operation .
- Content theft deterrent-Refer to Content Theft Deterrent (CTD) Description and Operation .
- Washer solvent level sensing-Refer to Wiper/Washer System Description and Operation .
- Wiper/washer-Refer to Wiper/Washer System Description and Operation .
Use the Manual With the Right Hardware
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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.
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