Body Control Module Description

CAUTION: Notice To Service Technicians, Dealership Personnel, and Plant Personnel, Engineering Does Not Recommend Swapping BCMs Between Vehicles Or With BCMs Off The Shelf.

The Body Control Module (PCM) is operational when supplied with battery power. The BCM controls various vehicle functions. It also supplies information to the instrument cluster to provide visual and audible information to the vehicle occupants. To provide and receive information the module interfaces with the vehicles serial bus communications network (PCI). This network consists of the:
- Integrated Power Module IPM, which incorporates the Power Distribution center PDC and the Front Control Module (FCM into one assembly
- Next Generation Controller (NGC), which incorporates the Powertrain Control Module (PCM) and the Transmission Control Module (TCM) into one module
- Mechanical Instrument Cluster (MIC)
- Electronic Vehicle Information Center (EVIC)
- Occupant Restraint Controller (ORC)
- Compass/Mini-Trip (CMTC)
- Overhead Console
- Controller Antilock Brake (CAB)
- Automatic Temperature Control Module (ATC)
- Power Liftgate Module (PLGM)
- Audio system
- Memory Heated Adjustable Pedal Module (MHSAPM)
- Memory Seat Adjustable Pedal Module (MSAPM)
- Remote Keyless Entry (RKE) and Sentry Key Immobilizer Module (SKREEM)
- Driver Door Module (DDM) and the Passenger Door Module (PDM) The BCM:
- Provides a battery protection feature.
- The BCM will send a message to the IPM to turn off all exterior lamps after 3 minutes and all interior lamps after 15 minutes after the ignition is turned of if they are not turned off by the driver.
- Provides Compass/Minitrip support.
- Provides interior lighting (courtesy/reading lamps).
- Provides diagnostic reporting.
- Provides electronic liftgate release (with power door locks).
- Provides exterior lighting.
- Provides headlamp time delay (with/without auto headlamps).
- Provides automatic headlamps (with electrochromatic mirror).
- Provides illuminated entry.
- Provides a fade to off feature.
- This feature dims the interior lighting (courtesy lamps) gradually if the BCM does not receive any new input that would cause the interior lamps to remain on.
- Provides PWM instrument panel dimming.
- Provides power liftgate switch input.
- The BCM has 1 Liftgate switch input located in the overhead console.
- Provides all stalk switch inputs including wipers and light switches.
- Provides seatbelt position input, indicating a buckled or unbuckled seatbelt.
- Provides turn signal operation.
- Provides fuel Level inputs.
- Monitors rear-door ajar switches, liftgate ajar switches, multifunction switches, multifunction headlight switch, ignition switch, PCI Bus, and diagnostic tool. Based on input from these components, the BCM will send requests over the PCI Bus to have the Instrument Cluster perform various chime operations.

The BCM has internal diagnostic capabilities that assist in diagnosing the vehicle's body system. When an "Open" or a "Short" circuit exists, the diagnostic tool can read the stored BCM Diagnostic Trouble Codes (DTCs). The DTCs are very descriptive in identifying the appropriate feature that has faulted.