BODY ELECTRICAL - SRS AIRBAG SYSTEM
D13N55
Occupant Classification ECU
Unoccupied: Judgment Value < A
OFF Signal
Front Passenger
Airbag
Front Passenger
Side Airbag
Front Passenger Seat
Belt Pretensioner
Airbag
Sensor
Assembly
AIRBAG OFF
Indicator Light
AIRBAG ON
Indicator Light
Front Passenger Seat
Belt Reminder Light
BE-139
4. System Operation
General
This system makes the following judgments: unoccupied judgment, child seat judgment, child judgment,
and adult judgment. In addition, it performs an initial check to check the circuit of the AIRBAG ON/ OFF
indicator lights when the power switch is IG-ON.
The occupant classification ECU constantly monitors the weight of the front passenger seat, and makes
a judgment in accordance with the signals from the occupant classification sensor and the state of the seat
belt buckle switch, regardless of the position of the power switch.
The occupant classification ECU contains criteria value A to judge whether the seat is being occupied
by a child or a child seat in accordance with the signals from the four occupant classification sensors and
seat belt buckle switch, and criteria value B to judge whether the occupant is an adult or child (with child
seat).
The occupant classification ECU makes an occupied or unoccupied judgment in accordance with the
signals from the seat belt buckle switch.
Unoccupied Judgment
The occupant classification ECU makes an unoccupied judgment when the judgment value is lower than
criteria value A and the seat belt buckle switch is OFF.
If the power switch is turned IG-ON in this state, the system performs an initial check, and does not
illuminate the AIRBAG ON/ OFF indicator lights. Then, the system prohibits the deployment of the front
passenger airbag, front passenger side airbag, and the front passenger seat belt pretensioner, and does not
blink the seat belt reminder light.
