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: Operation: Notes
The Body Control Module (BCM) supplies vehicle occupants with visual and audible information and controls various vehicle functions. To provide and receive information, the BCM is interfaced to the vehicle's serial bus communications network, referred to as the Programmable Communications Interface (PCI) bus.
This network consists of the;
- Powertrain Control Module (PCM)
- Transmission Control Module (TCM)
- Mechanical Instrument Cluster (MIC)
- Occupant Restraint Controller (ORC)
- Compass/Mini-Trip Computer (CMTC)
- Electronic Vehicle Information Center (EVIC)
- Controller Antilock Brake (CAB)
- HVAC Control Module
- Sliding Door Control Modules (driver and passenger side doors)
- Power Liftgate Module (PLG)
- Audio system equipped with RAZ, RBU, RBK, and RBB radios.
- Sentry Key Remote Entry Module (SKREEM).
- Side Impact Airbag Control Module (SIACM)
- Memory Seat Module (MSM)
- Sentry Key Immobilizer Module (SKIM)
The BCM is operational when battery power is supplied to the module.
The BCM provides the following features:
- Power Door Locks
- Automatic Door Locks
- Battery Protection - The BCM will automatically turn off all exterior lamps after 3 minutes, and all interior lamps after 15 minutes after the ignition is turned off, if they are not turned off by the driver.
- Chime Control
- Compass/Mini-Trip support.
- Interior Lighting (Courtesy/Reading Lamps)
- BCM Diagnostic Reporting
- Electronic Liftgate Release (with Power Door Locks)
- Exterior Lighting
- Headlamp Time Delay (with/without Automatic Headlamps)
- Illuminated Entry
- Fade to Off Interior Lamps - This feature dims the interior lighting (courtesy lamps) gradually if the BCM does not receive any new inputs that would cause the interior lamps to remain on.
- Pulse Width Modulated Instrument Panel Dimming
- Door Lock Inhibit - This feature disables the door lock functions if the key is in the ignition and either front door is ajar. Pressing the Remote Keyless Entry (RKE) lock/unlock button under these conditions result in normal lock/unlock activation.
The BCM has the ability to LEARN additional features in the vehicle, provided the appropriate switch input and PCI data bus messages are received. Refer to the LEARNED FEATURESΒ table.
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:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.
