Toyota 4Runner: System Description

Toyota 4Runner Service Manual / Vehicle Interior / Supplemental Restraint Systems / Occupant Classification System / System Description

SYSTEM DESCRIPTION

1. DESCRIPTION OF OCCUPANT CLASSIFICATION SYSTEM

(a) GENERAL DESCRIPTION

(1) In the occupant classification system, the occupant classification ECU calculates the weight of the occupant based on signals from the occupant classification sensors. This system recognizes the occupant to be a child if it detects a weight of less than 36 kg (79.4 lb), and disables the front passenger airbag assembly and side airbag (front passenger side).

(2) This system is mainly comprised of 4 occupant classification sensors that detect the load on the front passenger seat. The occupant classification ECU controls the system, and the passenger airbag ON/OFF indicator indicates the on/off status of the front passenger airbag and side airbag (front passenger side).

(b) OCCUPANT CLASSIFICATION SENSOR

(1) The occupant classification sensors are installed on 4 brackets connecting the seat rail and seat frame. Accordingly, when load is applied to the front passenger seat by an occupant sitting in it, the occupant classification sensors register a distortion.

(1) The passenger airbag ON/OFF indicator is installed on the air conditioning control assembly. This indicator informs the driver whether the occupant classification ECU will enable or disable the front passenger airbag assembly and side airbag (front passenger side).

(2) If a malfunction occurs in the occupant classification system, the passenger airbag ON/OFF indicator ("OFF") and SRS warning light will come on.

Initialization

INITIALIZATION 1. ZERO POINT CALIBRATION NOTICE: Make sure that the front passenger seat is not occupied before performing the operation. HINT: Perform the zero point calibration and sensitivit ...

Problem Symptoms Table

PROBLEM SYMPTOMS TABLE HINT: Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are lis ...

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REMOVAL PROCEDURE 1. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL CAUTION: Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system. NOTICE: When disconnecting the cable, some systems ne ...

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