Body Control Module: Description and Operation

DASH INTEGRATION MODULE (DIM)
The DIM is wired to the class 2 serial data circuit. The various DIM input and output circuits are described in the corresponding functional areas as indicated on the DIM electrical schematics.

The dash integration module (DIM) functions include the following:
- Control of exterior lamps.
- Hood ajar switch input w/export.
- Horn relay control for theft activation.
- Interior lamps and incandescent dimming.
- Low side temperature for the HVAC compressor.
- Power moding control over class 2 serial data circuit.
- Steering wheel controls.
- Storage of the clock settings and, sending a message out on the class 2 serial data circuit in response to requests from other modules.

The dash integration module (DIM) controls the exterior lighting and the horn activation. When the RIM detects an unauthorized entry, the RIM sends a message via the serial data circuit to the DIM to activate the horns and exterior lamps. The DIM then grounds the appropriate relays to control the exterior lighting and horns.

INSTRUMENT PANEL INTEGRATION MODULE (IPM)
The various IPM input and output circuits are described in the corresponding areas as indicated on the IPM electrical schematics.

The IPM functions include the following:
- Ambient light sensor input and twilight delay input for headlights control.
- Foglight switch inputs.
- Front HVAC air delivery and temperature controls.
- Fuel door and rear compartment lid release switch input.
- Ignition switch headlight control.
- Interior lamps switch input.
- I/P dimmer switch input.
- Key in ignition switch input from the ignition switch.
- Traction control switch input.

REAR INTEGRATION MODULE (RIM)
The various RIM inputs and outputs are described in the corresponding functional areas as indicated on the RIM electrical schematics.

The RIM functions include the following:
- Ajar switch and tamper switch inputs from the rear compartment lid.
- Content theft deterrent.
- Fuel door and rear compartment lid release controls.
- Fuel level sensor input.
- Heated seat controls.
- HVAC blower control.
- Park brake relay controls.
- Rear defogger control.
- Rear foglights control.
- Retained accessory power (RAP) relay control.
- Reverse control for the backup lamps and automatic day/night mirror.
- Various controls for the interior lamps.

The CTD system is an internal function of the Rear Integration Module (RIM) which utilizes class 2 serial data and various switch input information to perform CTD functions. When RIM detects an unauthorized entry, the RIM sends a message via the serial data circuit to the DIM to activate the horns and exterior lamps. The RIM has five basic modes (disarmed, standby, delayed, armed, and alarm) for operating the CTD system. The different modes are described below.

1. The RIM has the CTD system in a disarmed mode until the following conditions are detected:
- Ignition key turned to the OFF position
- Any door open
- Doors locked by either the power door lock switch or the LOCK button on the transmitter
2. The RIM enters the standby mode when the above conditions are detected. In standby mode the RIM commands the instrument cluster to illuminate the SECURITY indicator via the class 2 serial data line. (If all the doors are closed and the LOCK button on the transmitter is used, the RIM enters the delayed mode.
3. When the last door is closed, the RIM enters the delayed mode for 30 seconds. In delayed mode the RIM commands the instrument cluster to illuminate the SECURITY indicator via the class 2 serial data line.
4. After 30 seconds, the RIM enters the armed mode. In armed mode the RIM commands the instrument cluster to turn off the SECURITY indicator via the class 2 serial data line. Any forced entry activates the alarm mode.
5. When the RIM detects a forced entry, the RIM enters the alarm mode. The RIM commands the DIM to activate the horn and exterior lamps for 30 seconds, via a class 2 message. This is followed by a three minute time-out with the horn no longer active. If no new intrusions are detected after the time-out, the horn is not active. The system must be disarmed or the intrusion condition removed after the time-out for the system to exit alarm mode.