Operation

OPERATION

The Body Control Module (BCM) is operational when supplied with 12v 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 vehicle's Programmable Communication Interface (PCI) data bus network. This network consists of the:

- Audio system
- Automatic Temperature Control Module (ATC)
- Driver Door Module (DDM) and the Passenger Door Module (PDM)
- Compass/Mini-Trip Computer (CMTC)
- Electronic Vehicle Information Center (EVIC)
- Instrument Cluster (IC)
- Memory/Heated Seat Adjustable Pedal Module
- Overhead Console
- Sentry Key Remote Entry Module (SKREEM) - sometimes referred to as the Wireless Control Module (WCM), which performs the functions of the previous two modules - Remote Keyless Entry (RKE) and Sentry Key Immobilizer Module (SKIM). It also controls the Tire Pressure Monitoring (TPM) System.

To provide and receive information, the module interfaces with the vehicle's Controller Area Network (CAN) B, C, and D data bus networks. This network consists of the:

- Controller Anti-lock Brake (CAB)
- 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.
- Occupant Restraint Controller (ORC)
- Power Liftgate Module (PLGM)

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 off, if they are not turned off by the driver
- 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
- All stalk switch inputs including wipers and light switches
- Automatic headlamps (with electro-chromatic mirror)
- Compass/Mini-trip support
- Diagnostic reporting
- Electronic liftgate release (with power door locks)
- Exterior lighting
- Fuel Level inputs
- Headlamp time delay (with/without auto headlamps)
- Illuminated entry
- Interior lighting (courtesy/reading lamps)
- Power liftgate switch input. - The BCM has 1 Liftgate switch input located in the overhead console
- Pulse Width Modulated (PWM) instrument panel dimming
- Seat belt position input, indicating a buckled or unbuckled seat belt
- Turn signal operation
- Monitors rear-door ajar switches, liftgate ajar switches, multi-function switches, multi-function 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 scan tool can read the stored BCM Diagnostic Trouble Codes (DTC's). The DTC's are very descriptive in identifying the appropriate feature that has faulted. Use a scan tool and the appropriate diagnostic information.

NOTE: If the BCM is replaced, it must be programmed using a scan tool and DealerCONNECT(R).