Data Line Communications

The body control module (BCM) communicates on the following 2 separate data lines:

• Class 2 serial data comminutions - Refer to Data Link Communications Description and Operation .
• Serial peripheral interface (SPI) - The BCM acts as the master between itself and the instrument panel cluster (IPC).

The various BCM input and output circuits are described in the corresponding functional areas indicated on the BCM electrical schematics. The BCM functions include the following:

• A/C compressor request - Refer to Air Temperature Description and Operation in HVAC Systems - Manual.
• Remote function control - Refer to Keyless Entry System Description and Operation in Keyless Entry.
• A/C cooling fan
• Audio delay power - Refer to Radio/Audio System Description and Operation in Entertainment.
• Exterior and interior lighting control - Refer to Exterior Lighting Systems Description and Operation in Lighting Systems.
  • Daytime running lamps (DRL)
  • Automatic lighting control
  • Fog lamps
• Interior lighting - Refer to Interior Lighting Systems Description and Operation in Lighting Systems.
• Battery rundown protection from inadvertent power - Refer to Interior Lighting Systems Description and Operation in Lighting Systems.
• Chimes - Refer to Audible Warnings Description and Operation in Instrument Panel, Gages, and Console.
  • Key-in-Ignition
  • Head Lamps On
  • Seat Belt Not Fastened
  • Turn Signal On
  • Park Brake Warning
  • Door Ajar Warning
  • Check Gages
• Gage control - Refer to Instrument Panel Cluster (IPC) Description and Operation in Instrument Panel, Gages, and Console.
• Instrument cluster indicator control - Refer to Instrument Panel Cluster (IPC) Description and Operation In Instrument Panel, Gages, and Console.
• Theft deterrent - Refer to Theft Systems Description and Operation in Theft Deterrent.
• Engine coolant level sensing - Refer to Cooling System Description and Operation in Engine Cooling.
• Washer solvent level sensing - Refer to Wiper/Washer System Description and Operation in Wipers/Washer Systems.
• Key-in-ignition sensing - Refer to Audible Warnings Description and Operation in Instrument Panel, Gages, and Console.
• Seat belt use sensing - Refer to Seat Belt System Description and Operation in Seat Belts.
• Brake fluid level sensing - Refer to Brake Warning System Description and Operation in Hydraulic Brakes.
• Parking brake state sensing - Refer to Brake Warning System Description and Operation in Hydraulic Brakes.
• Rear compartment interface - Refer to Power Door Locks Description and Operation in Doors.
• Horn interface - Refer to Horns System Description and Operation in Horns.
• Door lock interface - Refer to Power Door Locks Description and Operation in Doors.
• Bulb check - Refer to Instrument Panel Cluster (IPC) Description and Operation in Instrument Panel, Gages, and Console.