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) data bus.

This network consists of the;

• Audio system equipped with RBQ radio.
• Controller Antilock Brake (CAB)
• ElectroMechanical Instrument Cluster (EMIC)
• HVAC Control Module
• Occupant Restraint Controller (ORC)
• Powertrain Control Module (PCM)

The BCM is operational when battery power is supplied to the module and after the ignition is FIRST powered to RUN or the driver side exterior door handle is pressed.

The BCM provides the following features:

• 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.
• Battery Save Mode
• BCM Diagnostic Reporting
• Chime Control
• Deck lid Release (RKE only)
• Door Entry
• 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.
• Exterior Lighting
• 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.
• Fuel Level
• Headlamp Time Delay
• Horn
• Ignition Switch Status
• Illuminated Entry
• Interior Lighting (Courtesy/Reading Lamps)
• Power Door Virtual Locks
• Power Windows - Includes Auto Down feature
• Pulse Width Modulated Instrument Panel Dimming
• Remote Keyless Entry (RKE)
• Smart Glass
• Tire Pressure Fault Detection
• Vehicle Theft Security
• Virtual Lock Automatic Door Locks

All features on the BCM are standard except Daytime Running Lamps (DRL). The customer/dealer has the ability enable or disable the following features:

• Auto Lock Disable
• Daytime Running Lamps Enable (U.S. - Option, Canada - Enabled)
• Headlamp Delay Disable
• Power Accessory Delay Disable
• RKE Horn Chirp Disable
• RKE Optical chirp Disable
• RKE Unlock - All - one press Enable

The BCM has internal diagnostic capability that assists in diagnosing the system error. When an OPEN or a SHORT circuit exists, the diagnostic tool can be used to read the BCM faults. The faults are very descriptive in identifying the appropriate feature that has faulted.

The only two faults that the BCM logs that conclude the replacement of a BCM are faults;

• # 06 - Internal BCM failure (replace BCM)
• # 31 - J1850 Internal Hardware Failure (replace BCM)

Otherwise the appropriate diagnostic procedures for each of the features should be taken when the BCM logs a fault. Refer to BODY DIAGNOSTIC PROCEDURES .