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Home >> Lexus >> 2008 >> GS 450h >> Repair and Diagnosis >> Restraints >> Air Bag, SRS >> Supplemental Restraint System >> Airbag System >> Precaution

Airbag System: Precaution

CAUTION:
  • The vehicle is equipped with a Supplemental Restraint System (SRS), which consists of a steering pad, front passenger airbag, curtain shield airbag, front seat side airbag, driver side knee airbag, front passenger side knee airbag, rear seat airbag, seat belt pretensioner, center airbag sensor, front airbag sensor, side airbag sensor, rear airbag sensor, seat position airbag sensor and occupant classification ECU. Failure to carry out service procedures in the correct sequence could cause SRS parts to unexpectedly deploy and possibly lead to serious injuries. Furthermore, if a mistake is made when servicing SRS parts, they may fail to operate when required. Before performing servicing (including installation/removal, inspection and replacement of parts), be sure to read the following precautions.
  • Before starting work, wait at least 90 seconds after the power switch is turned OFF and after the cable of the negative (-) battery terminal is disconnected. (SRS parts are equipped with a backup power source. If work is started within 90 seconds of turning the power switch OFF and disconnecting the cable from the negative (-) battery terminal, SRS parts may deploy.)
  • Do not expose SRS parts directly to hot air or flames.
NOTE:
  • Malfunction symptoms of SRS parts are difficult to confirm. DTCs are the most important source of information when troubleshooting. During troubleshooting, always confirm DTCs before disconnecting the cable from the negative (-) battery terminal.
  • For minor collisions where SRS parts do not deploy, always inspect the SRS parts.
  • Before performing repairs, remove airbag sensors as necessary if any kind of impact is likely to occur to an airbag sensor during repairs.
  • Never use SRS parts from another vehicle. When replacing SRS parts, replace them with new ones.
  • Never disassemble or attempt to repair SRS parts.
  • If an SRS part has been dropped, or if there are any cracks, dents or other defects in the case, bracket or connector, replace the SRS part with a new one.
  • Use an ohmmeter/voltmeter with high impedance (10 kΩ/V minimum) for troubleshooting the electrical circuits.
  • Information labels are attached to the periphery of SRS parts. Follow the cautions and instructions on the labels.
  • After work on SRS parts is completed, perform the SRS warning light check (see DIAGNOSIS SYSTEM  ).
  • When the cable is disconnected from the negative (-) battery terminal, the memory settings of each system will be cleared. Because of this, be sure to write down the settings of each system before starting work. When work is finished, reset the settings of each system as before. Never use a backup power supply from outside the vehicle to avoid erasing the memory in a system.
  • If the vehicle is equipped with a mobile communication system, refer to the PRECAUTION in the INTRODUCTION article.
  • When disconnecting the negative (-) battery cable, initialize the following systems after the cable is reconnected.
SYSTEM NAME REFERENCE CHART

System Name See procedure
Intuitive Parking Assist System INITIALIZATION
Power Window Control System
Variable Gear Ratio Steering System

HINT:

In the airbag system, the center airbag sensor, front airbag sensor LH and RH, side airbag sensor LH and RH, rear airbag sensor LH and RH are collectively referred to as the airbag sensors.

  1. HANDLING PRECAUTIONS FOR AIRBAG SENSORS 
    1. Before starting the following operations, wait for at least 90 seconds after disconnecting the negative (-) terminal cable from the battery:
      1. Replacement of the airbag sensors.
      2. Adjustment of the front/rear doors of the vehicle equipped with the side airbag and curtain shield airbag (fitting adjustment).
    2. When connecting or disconnecting the airbag sensor connectors, ensure that each sensor is installed in the vehicle.
    3. Do not use the airbag sensors which has been dropped during the operation or transportation.
    4. Do not disassemble the airbag sensors.
  2. INSPECTION PROCEDURE FOR VEHICLE INVOLVED IN ACCIDENT 
    1. When the airbag has not deployed, confirm the DTCs by checking the SRS warning light. If there is any malfunction in the SRS airbag system, perform troubleshooting.
    2. When any of the airbags have deployed, replace the airbag sensors and check the installation condition.
  3. SRS CONNECTORS 
    1. SRS connectors are located as shown in the following illustration.
      Fig 1: Airbag System Diagram (For Driver Side)
      G05817023Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      Fig 2: Airbag System Diagram (For Passenger Side)
      G05817024Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      ITEM APPLICATION CHART

      No. Item Application
      (1) Terminal Twin-Lock Mechanism Connectors 5, 6, 7, 8, 9, 10, 19, 20, 31, 32, 33, 34
      (2) Activation Prevention Mechanism Connectors 10, 12, 14, 20, 22, 26, 30, 32, 34
      (3) Half Connection Prevention Mechanism Connectors 5, 7, 9, 20, 24, 28, 32, 33
      (4) Connector Position Assurance Mechanism Connector 7
      (5) Connector Lock Mechanism (1) Connectors 11, 13, 21, 25, 29
      (6) Connector Lock Mechanism (2) Connector 2, 4
      (7) Improper Connection Prevention Lock Mechanism Connector 1, 3
    2. All connectors in the SRS, except the seat position airbag sensor connector, are colored yellow to distinguish them from other connectors. These connectors have special functions, and are specially designed for the SRS. All SRS connectors use durable gold-plated terminals, and are placed in the locations shown below to ensure high reliability.
      1. Terminal twin-lock mechanism:

        All connectors with a terminal twin-lock mechanism have a two-piece component consisting of a housing and a spacer. This design enables the terminal to be locked securely by two locking devices (the retainer and the lance) to prevent terminals from coming out.

        Fig 3: Identifying Terminal Twin-Lock Mechanism
        G05817025Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      2. Activation prevention mechanism:

        All connectors with an activation prevention mechanism contain a short spring plate. When these connectors are disconnected, the short spring plate creates a short circuit by automatically connecting the positive (+) and negative (-) terminals of the squib.

        Fig 4: Identifying Activation Prevention Mechanism
        G05817026Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      3. Half connection prevention mechanism:

        If the connector is not completely connected, the connector is disconnected due to the spring operation so that no continuity exists.

        Fig 5: Identifying Half Connection Prevention Mechanism
        G05817027Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      4. Connector position assurance mechanism:

        Only when the housing lock (white part) is completely engaged, the CPA (yellow part) slides, which completes the connector engagement.

        Fig 6: Identifying Connector Position Assurance Mechanism
        G05817028Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      5. Connector lock mechanism (1):

        Locking the connector lock button connects the connector securely.

        Fig 7: Identifying Connector Lock Mechanism
        G05817029Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      6. Connector lock mechanism (2):

        Both the primary lock with holder lances and the secondary lock with retainer prevent the connectors from becoming disconnected.

        Fig 8: Identifying Connector Lock Mechanism
        G05817030Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      7. Improper connection prevention lock mechanism:

        When connecting the holder, the lever is pushed into the lock position by rotating around the A axis to lock the holder securely.

        Fig 9: Identifying Improper Connection Prevention Lock Mechanism
        G05817031Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  4. DISCONNECTION OF CONNECTORS FOR STEERING PAD, FRONT PASSENGER AIRBAG (SQUIB SIDE), DRIVER SIDE KNEE AIRBAG, FRONT PASSENGER SIDE KNEE AIRBAG, CURTAIN SHIELD AIRBAG, FRONT SEAT OUTER BELT AND REAR SEAT OUTER BELT 

    HINT:

    Tape the screwdriver tip before use.

    1. Release the lock button (yellow part) of the connector using a screwdriver.
    2. Insert the screwdriver tip between the connector and the base, and then raise the connector.
      Fig 10: Inserting Screwdriver Tip Between Connector And Base
      G05817032Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  5. CONNECTION OF CONNECTORS FOR STEERING PAD, FRONT PASSENGER AIRBAG (SQUIB SIDE), DRIVER SIDE KNEE AIRBAG, FRONT PASSENGER SIDE KNEE AIRBAG, CURTAIN SHIELD AIRBAG, FRONT SEAT OUTER BELT AND REAR SEAT OUTER BELT 
    1. Connect the connector.
    2. Push down securely on the lock button (yellow part) of the connector. (When locking, a click sound can be heard.)
      Fig 11: Pushing Down Lock Button
      G05817033Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  6. DISCONNECTION OF CONNECTOR FOR FRONT PASSENGER AIRBAG (INSTRUMENT PANEL WIRE SIDE) 
    1. Place a finger on the slider, slide the slider to release the lock, and then disconnect the connector.
      Fig 12: Placing Finger On Slider
      G05817034Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  7. CONNECTION OF CONNECTOR FOR FRONT PASSENGER AIRBAG (INSTRUMENT PANEL WIRE SIDE) 
    1. Connect the connector as shown in the illustration. (When locking, make sure that the slider returns to its original position and a click sound can be heard.)

      HINT:

      When connecting, the slider will slide. Be sure not to touch the slider while connecting, as it may result in an insecure fit.

      Fig 13: Connecting Connector
      G05817035Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  8. DISCONNECTION OF CONNECTORS FOR FRONT SEAT AIRBAG AND REAR SEAT AIRBAG 
    1. Place a finger on the slider, slide the slider to release the lock, and then disconnect the connector.
      Fig 14: Placing Finger On Slider
      G05817036Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  9. CONNECTION OF CONNECTORS FOR FRONT SEAT AIRBAG AND REAR SEAT AIRBAG 
    1. Connect the connector as shown in the illustration. (When locking, make sure that the slider returns to its original position and a click sound can be heard.)

      HINT:

      When connecting, the slider will slide. Be sure not to touch the slider while connecting, as it may result in an insecure fit.

      Fig 15: Connecting Connector
      G05817037Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  10. DISCONNECTION OF CONNECTOR FOR CENTER AIRBAG SENSOR 

    HINT:

    Perform the following procedures when replacing the holder.

    1. Pull the lever by pushing part A as shown in the illustration and disconnect the holder (with connectors).
      Fig 16: Pulling Lever
      G05817038Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Remove the holder.
      1. Using a screwdriver, unlock the retainer.
        Fig 17: Unlocking Retainer
        G05817039Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      2. Release the fitting lance and remove the holder.
        Fig 18: Removing Fitting Lance
        G05817040Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Install the holder.
      1. Install the connectors to the holder. (When locking, a click sound can be heard.)

        HINT:

        The retainer is locked when the holder is connected.

  11. CONNECTION OF CONNECTOR FOR CENTER AIRBAG SENSOR 
    1. Firmly insert the holder (with connectors) into the center airbag sensor until it cannot be pushed any further.
      Fig 19: Inserting Holder (With Connectors) Into Center Airbag Sensor
      G05817041Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Push the lever to connect the holder (with connectors). (When locking, a click sound can be heard.)

      HINT:

      The holder slides into the center airbag sensor when it is being connected. Be sure not to hold the holder while connecting, as it may result in an insecure fit.

      Fig 20: Pushing Lever To Connect Holder
      G05817042Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  12. DISCONNECTION OF CONNECTOR FOR FRONT AIRBAG SENSOR 
    1. Push down the housing lock (white part) and slide the GPA (yellow part). (At this time, the connector cannot be disconnected yet.)
    2. Push down the housing lock (white part) again and disconnect the connector.

      HINT:

      Do not push down the A part shown in the illustration when disconnecting.

      Fig 21: Pushing Down Housing Lock
      G05817043Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. After disconnecting the connector, check that the position of the housing lock (white part) is as shown in the illustration.
      Fig 22: Identifying Correct And Incorrect Position Of Housing Lock
      G05817044Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  13. CONNECTION OF CONNECTOR FOR FRONT AIRBAG SENSOR 
    1. Before connecting the connectors, check that the position of the housing lock (white part) is as shown in the illustration.
      Fig 23: Identifying Correct And Incorrect Position Of Housing Lock
      G05817045Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Be sure to engage the connectors until they are locked. (When locking, make sure that a click sound can be heard.)

      HINT:

      When connecting them, the housing lock (white part) slides. Be sure not to hold the housing lock (white part) and the part labeled A, as it may result in an insecure fit.

      Fig 24: Engaging Connectors
      G05817046Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  14. DISCONNECTION OF CONNECTORS FOR SIDE AIRBAG SENSOR AND REAR AIRBAG SENSOR 
    1. While holding both the sides of the outer connector locking sleeve, slide the sleeve in the direction shown by the arrow.
    2. When the connector lock is released, the connectors are disconnected.

      HINT:

      Be sure to hold both sides of the sleeve. Holding the top and bottom will make disconnection difficult.

      Fig 25: Sliding Sleeve
      G05817047Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      Fig 26: Releasing Connector
      G05817048Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  15. CONNECTION OF CONNECTORS FOR SIDE AIRBAG SENSOR AND REAR AIRBAG SENSOR 
    1. Connect the connector as shown in the illustration (When locking, make sure that the outer connector locking sleeve returns to its original position and a click sound can be heard).

      HINT:

      When connecting, the sleeve will slide. Be sure not to hold the sleeve while connecting, as it may result in an insecure fit.

      Fig 27: Connecting Connector
      G05817049Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002