Body Control Module

The body control module (BCM) supplies vehicle occupants with visual and audible information and controls various vehicle functions. To provide and receive information, the module is interfaced to the vehicle's serial bus communications network (PCI). This network consists of the powertrain control module (PCM), the engine control module (ECM) diesel, the mechanical instrument cluster (MIC), the front control module (FCM), the occupant restraint controller (ORC), the occupant classification module (OCM), the overhead console, the ABS module, the hands free module (HFM), the park assist module, the HVAC control module (ATC & MTC), the power sliding door (Left & Right) modules (PSD), the power liftgate module (PLG), the Audio system (which includes the Radio, DVD, CD Changer and Amplifier), the memory seat/mirror/adjustable pedals module (MSMAPM), the RKE/that cham alarm module (export), the transmission control module (Diesel only) and the sentry key remote entry module (SKREEM). The BCM is operational when battery power is supplied to the module.

The body control module provides the following features:

• Power Door Locks
• Automatic Door Lock
• Door Lock Inhibit
• Central Locking (with VTSS Only)
• 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 Driver
• Compass/Minitrip Support
• Interior Lighting (Courtesy/Reading Lamps)
• BCM Diagnostic Reporting
• Electronic Liftgate Release (with Power Door Locks)
• Exterior Lighting
• Headlamp Time Delay (with/without Autohead-lamps)
• Automatic Headlamps (with electrochromatic mirror)
• Illuminated Entry
• Fade to Off

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.

• PWM 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 RKE lock/unlock button under these conditions, result in normal lock/unlock activation.

• Power Sliding Door Switch Inputs

The BCM has 4 switch inputs for the power sliding door feature: Located in the overhead console are the Left and Right side sliding door switches to activate either or both sliding doors under the proper conditions. Also there are B-Pillar switches located on the Left and Right B-pillar posts.

• Power Liftgate Switch Input

The BCM has 1 Liftgate switch input located in the overhead console

• Power Lockout Switch Input

The BCM has 1 Lockout switch that when enabled will disable the B-Pillar sliding door switches from activating either sliding door when depressed. When replacing a body control module there are 2 modules available, a Base and a Midline. The Midline controller is used on vehicles that have Power Door Locks. If a vehicle is equipped with the Vehicle Theft Security System, the midline controller becomes a premium when the theft feature is enabled.

Engineering does not recommend that service, dealers or the plant swap Body Control Modules (BCM) between vehicles or off the shelf. The BCM has internal diagnostic capability that assists in diagnosing the system. When an "Open" or a "Short" circuit exists, the diagnostic tool can be used to read the BCM codes. The codes are very descriptive in identifying the appropriate feature that has faulted. The BCM also learns what features are on the vehicle and if modules are swapped the BCM could set false DTCs based on what it learned.