OCCUPANT CLASSIFICATION SENSOR [TWO-STEP DEPLOYMENT CONTROL SYSTEM]

2016 – MX-5 – Restraints

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 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 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 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 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 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 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 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.

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

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)

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)

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

The occupant classification sensor detects the presence of an occupant in the passenger’s seat using the electronic control unit based on the information detected by the sensor mat.
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 PASSENGER SENSING SYSTEM [TWO-STEP DEPLOYMENT CONTROL SYSTEM].)

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