OCCUPANT CLASSIFICATION SENSOR [TWO-STEP DEPLOYMENT CONTROL SYSTEM]


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Warning
•  If an additional, thick seat cushion is placed on the seat cushion, the occupant classification sensor will determine that there are no occupants (child is seated on child-restraint seat or seat is unoccupied) and, as a result, the air bag may not operate (deploy). If an occupant (adult) is to be seated in the front passenger’s seat, do not place an additional thick cushion on the seat cushion.
•  If the occupant is seated in an extremely unusual manner, such as at the front of the seat, the occupant classification sensor will determine that there are no occupants (child is seated on child-restraint seat or seat is unoccupied) even if the occupant (adult) is seated on the front passenger’s seat because the area of the seated occupant is smaller and, as a result, the air bag may not operate (deploy) if the vehicle is involved in a collision. If an occupant is seated in the front passenger’s seat, verify that they are seated in the correct posture.
•  If the seat cushion becomes dampened, the occupant classification sensor will determine that the front passenger’s seat is occupied by a child or unoccupied, or that an occupant (adult) is seated and, as a result, the air bag may operate (deploy) if the vehicle is involved in a collision. If the front passenger’s seat has been dampened, do not seat a child requiring a child-restraint seat on the seat.
Caution
•  If an object with a high dialectic constant (such as bottled liquid) is placed on the front passenger’s seat, the occupant classification sensor will determine that an occupant (adult) is seated and, as a result, the air bag may operate (deploy) if the vehicle is involved in a collision.
•  If an electric device such as a personal computer is placed on the front passenger’s seat, the occupant classification sensor will determine that an occupant (adult) is seated and, as a result, the air bag may operate (deploy) if the vehicle is involved in a collision even if the seat is unoccupied.

Purpose

•  The occupant classification sensor measures the capacitance to detect the presence of an occupant on the front passenger’s seat, and sends the front passenger’s seat status signal to the SAS control module via CAN communication.

Function


Detection function

•  Because the capacitance changes according to the following, the occupant classification sensor detects the presence of an occupant based on the change amount.
―  Dialectic constant of sensor mat and material (such as cushion material and occupant clothing) between sensor mat
―  Area of sensor mat matching area (buttocks, thigh) of seated occupant
―  Distance between sensor mat and occupant (buttocks, thigh)
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Detected information transmitting function

•  The capacitance sensor sends the detected information to the SAS control module via CAN communication.

Detected information

Signal

Occupant (adult) is detected
Passenger seat status signal (adult)
No occupant (child is seated on child-restraint seat or unoccupied) is detected
Passenger seat status signal (child)


Structure/Construction

•  The occupant classification sensor is located in the seat cushion of the front passenger’s seat.
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•  The occupant classification sensor consists of an electronic control unit and the sensor mat.

Operation

1.  The occupant classification sensor detects the presence of an occupant in the front passenger’s seat using the electronic control unit based on the information detected by the sensor mat.
2.  The occupant classification sensor sends the detected information to the SAS control module.
Note
•  The SAS control module performs air bag system control based on the signal sent from the occupant classification sensor. (See AIR BAG SYSTEM [TWO-STEP DEPLOYMENT CONTROL SYSTEM].)
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Fail-safe

•  If a malfunction occurs in the occupant classification sensor, the occupant classification sensor sends malfunction information to the SAS control module.