Body Control Module - Description

DESCRIPTION





The Body Control Module (BCM) (2) for this vehicle is located within the instrument panel to the left of the steering column. the BCM houses a small fuse block on the front of the module that house fuses for many of the systems that the BCM supports. The main body of the BCM, including the mounts and the electrical connections, are concealed within the instrument panel.

VEHICLE SYSTEMS SUPPORT
The electronic functions of the BCM supports or controls, include the following:
- Electric Backlight Control - The BCM monitors hard-wired inputs from the Electric Backlight (EBL) switch to control timing and function of the electric backlight.
- Exterior Lighting Control - The BCM monitors electronic messages and hard-wired inputs from the exterior lighting switch to provide lamp control.
- Front and Rear Wiper Control - The BCM monitors inputs from the front and rear wiper switch to provide control of the either the front or rear wiper motors. The BCM also controls the intermittent wiper feature of the front wiper system.
- Heated Seat Control - On vehicles equipped with optional heated seats, the BCM monitors hard-wired inputs from the heated seat switches to control the ON/OFF functions of the heated seats.
- Interior Lighting Control - The BCM monitors hard-wired inputs from the interior lighting switch, the door ajar switches, the liftgate ajar switch, and the reading lamp switches to provide courtesy lamp control.
- Local Interface Network Master Module - The BCM is the master module for the LIN data bus on vehicles equipped with a retractable convertible top (Cabrio). In this role it gathers information from the power retractable top module and then either acts on that information directly or places electronic messages on the CAN data bus for use by other modules
- Power Lock System Control - The BCM monitors inputs from the power lock switches to provide control of the power lock motors through high side and low side driver outputs. This includes support for rolling door locks (also known as automatic door locks), automatic door unlock, and a door lock inhibit mode.
- Power Window System control - The BCM monitors inputs from the power window switches to provide control of the power window motors.
- Remote Keyless Entry Support - The BCM supports the Remote Keyless Entry (RKE) system features, including support for the RKE LOCK, UNLOCK (with optional driver-door-only unlock, and unlock-all-doors), PANIC, audible chirp, optical chirp, illuminated entry modes, an RKE programming mode.
- Vehicle Theft Security System Control - The BCM monitors inputs from the door ajar switches, and the intrusion module provides electronic horn and lighting request messages to the BCM for the appropriate VTSS alarm output features.
- Washer System Control - The BCM monitors inputs from the power window switches to provide control of the bi-directional pump for either the front or rear washer system.
In addition to vehicle system support, the BCM also monitors the following systems or sensors within the vehicle, and transmits the information received over the Control Area Network (CAN) data bus to other modules.
- A/C Signal Request
- Ambient Temperature Sensor
- Brake Fluid Level Sensor
- Cruise Control Switch
- Door Ajar Switch
- Fuel Level Sensor
- Steering Wheel Mounted Switches

The BCM also houses several relays used to control many of the features previously discussed. The relays controlled by the BCM are not serviceable, If any relay within the BCM becomes damaged or ineffective, the entire assembly must be replaced. Body Control Module - Removal for more information.