Description & Operation

WARNING: Vehicle is equipped with air bag supplemental restraint system. Before attempting ANY repairs involving steering column, instrument panel or related components, see SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM in TOYOTA - AIR BAG RESTRAINT SYSTEMS article.

CAUTION: When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery.

The body control system consists of the body control Electronic Control Unit (ECU). Body control ECU controls the following systems:

Key unlock warning system and buzzer.
Headlight and taillight systems, including auto headlight off system and daytime running lights.
Multi-display information center.
Luggage compartment (trunk) release system.
Automatic light control system.
Illuminated entry system.
Theft deterrent system.
Seat belt warning system.
Power door lock system.
Automatic door lock/unlock system.
Wireless door lock (remote keyless) control system.
Warning systems and buzzers.

The body control ECU, along with driver door ECU and front passenger door ECU, have support role in control of theft deterrent system. The theft deterrent ECU has primary control over theft deterrent system. Always begin diagnosis of the theft deterrent system by checking the multiplex communication system. See MULTIPLEX CONTROL SYSTEMS - AVALON article under COMMUNICATION DEVICES in ACCESSORIES & EQUIPMENT.

Driver door ECU and front passenger door ECU control power window system. Driver door ECU and passenger door ECU have support role in control of power door lock system. Always begin diagnosis of the power window system by checking the multiplex communication system. See MULTIPLEX CONTROL SYSTEMS - AVALON article under COMMUNICATION DEVICES in ACCESSORIES & EQUIPMENT.