Supplemental Restraint System: Precaution

CAUTION:

The vehicle is equipped with a Supplemental Restraint System (SRS). It consists of a driver airbag, front passenger airbag, driver knee airbag, side airbag and curtain shield airbag. Failure to carry out service operations in the correct sequence could cause the SRS to unexpectedly deploy during servicing, possibly leading to a serious accident. Further, if a mistake is made in servicing the SRS, it is possible that the SRS may fail to operate when required. Before performing servicing (including removal or installation of parts, inspection or replacement), be sure to read the following items carefully, then follow the correct procedures indicated in the repair manual.
Wait at least 90 seconds after the ignition switch is turned off and the negative (-) terminal cable is disconnected from the battery before starting the operation.
(The SRS is equipped with a backup power source, so that if work is started within 90 seconds after disconnecting the negative (-) terminal cable of the battery, the SRS may be deployed.)
Do not expose the horn button assy, front passenger airbag assy, instrument panel airbag assy lower No.1, airbag sensor assy center, airbag sensor front, front seat airbag assy, side airbag sensor assy, curtain shield airbag assy, airbag sensor rear, seat position airbag sensor or occupant classification ECU directly to hot air or flames.
Be sure to perform the initialization of the occupant classification ECU if any of the following conditions occur (see INITIALIZATION ). If the initialization is not performed, the SRS may not operate properly.
- The occupant classification ECU is replaced.
- Accessories (seatback tray, seat cover, etc.) are installed to the vehicle.
- The passenger seat is removed from the vehicle, and then reinstalled or replaced.
- The passenger airbag ON/OFF indicator light ("OFF") comes on when the passenger seat is not occupied.
- The vehicle is brought to the workshop for repair due to an accident or collision.

NOTE:

Malfunction symptoms of the SRS are difficult to confirm, so DTCs are the most important source of information when troubleshooting. When troubleshooting the SRS, always inspect DTCs before disconnecting the battery.
Even in the case of a minor collision when the SRS does not deploy, the horn button assy, front passenger airbag assy, instrument panel airbag assy lower No.1, airbag sensor assy center, airbag sensor front, front seat airbag assy, side airbag sensor assy, curtain shield airbag assy, airbag sensor rear, seat position airbag sensor and occupant classification ECU should be inspected (see ON-VEHICLE INSPECTION ).
Before repair work, remove the airbag sensor if any kind of shock is likely to occur to the airbag sensor during the repair.
Never use SRS parts from another vehicle. When replacing parts, replace them with new ones.
Never disassemble or repair any of the following parts in order to reuse them. If any of these parts have been dropped, or a defect is found (e.g. cracks, dents or any other defects) in any of the housings, brackets or connectors, then replace the part with a new one.
- Horn Button Assy
- Front Passenger Airbag Assy
- Instrument Panel Airbag Assy Lower No.1
- Front Seat Airbag Assy
- Curtain Shield Airbag Assy
- Airbag Sensor Assy Center
- Airbag Sensor Front
- Side Airbag Sensor Assy
- Airbag Sensor Rear
- Seat Position Airbag Sensor
- Occupant Classification ECU

NOTE:

Use a volt/ohmmeter with high impedance (10 kΩ/V minimum) for troubleshooting the electrical circuits.
Information labels are attached near the SRS components. Follow the instructions in the caution.
After work on the SRS is completed, perform the SRS warning light check (see DIAGNOSIS SYSTEM ).
When the negative (-) terminal cable is disconnected from the battery, the memory will be cleared. Because of this, be sure to make a record of the contents memorized in each system before starting work. When work is finished, adjust each system as it was before. Never attempt to avoid erasing vehicle system memories by using a backup power supply from outside the vehicle.
If the vehicle is equipped with a mobile communication system, see PRECAUTION .
When disconnecting the negative (-) battery terminal, initialize the following systems after the terminal is reconnected.

POWER WINDOW CONTROL SYSTEM REFERENCE

System Name	See
Power Window Control System	INITIALIZATION
Sliding Roof System	INITIALIZATION

EXPRESSIONS OF IGNITION SWITCH

The type of ignition switch used on this model differs according to the specifications of the vehicle. The expressions listed in the table below are used in this section.

IGNITION SWITCH SPECIFICATIONS

Expression: Switch Type	Ignition Switch (position)	Engine Switch (condition)
Ignition Switch off	LOCK	Off
Ignition Switch on (IG)	ON	On (IG)
Ignition Switch on (ACC)	ACC	On (ACC)
Engine Start	START	Start

DEPLOYMENT CONDITION
When the vehicle collides and the shock is greater than the specified value, the SRS is activated automatically. The airbag sensor assy center includes the safing sensor and deceleration sensor. The safing sensor was designed to be turned on at a smaller deceleration rate than the deceleration sensor.
1. The airbag sensor assy center determines whether or not ignition is necessary based on signals from the deceleration sensor and the airbag sensor front. (*) If the safing sensor turns on simultaneously, current flows to the squibs to deploy the SRS as shown in the illustration below.
  
  Fig 1: Front Airbag Sensor Assy Diagram
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. The airbag sensor assy center determines whether or not ignition is necessary based on signals from the side airbag sensor assy. If the safing sensor turns on simultaneously, current flows to the squib to deploy the SRS as shown in the illustration below.
  
  Fig 2: Side Airbag Sensor Assy Diagram
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. The airbag sensor assy center determines whether or not ignition is necessary based on signals from the airbag sensor rear. If the safing sensor turns on simultaneously, current flows to the squib to deploy the SRS as shown in the illustration below. (*)
  
  Fig 3: Front Airbag Sensor Assy Diagram
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

SRS CONNECTORS

HINT:

SRS connectors are located as shown in the following illustration.

Fig 4: SRS Connectors Diagram

SRS CONNECTORS REFERENCE

No.	Connector Type	Application
(1)	Terminal Twin-Lock Mechanism	Connectors 6, 8, 10, 12, 15, 16, 17, 18, 19, 21, 22, 27, 28, 32
(2)	Activation Prevention Mechanism	Connectors 20, 22, 24, 26, 28, 30, 32, 34
(3)	Half Connection Prevention Mechanism	Connectors 6, 8, 10, 16, 19, 21, 27, 31
(4)	Connector Position Assurance Mechanism	Connector 6
(5)	Connector Lock Mechanism (1)	Connectors 23, 25, 29, 31, 33
(6)	Connector Lock Mechanism (2)	Connectors 2, 4
(7)	Improper Connection Prevention Lock Mechanism	Connectors 1, 3

All connectors in the SRS, except the seat position airbag sensor connector and the occupant classification ECU connectors, 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 on the previous page 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.
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 5: Identifying Two-Piece Component Consisting Of Housing And Spacer
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 6: Disconnecting Short Spring Plate
  Courtesy 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 7: Identifying Stopper
  Courtesy 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 8: Identifying Housing Lock (White Part) and CPA (Yellow Part)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
5. Connector lock mechanism (1):
  Locking the connector lock button connects the connector securely.
  
  Fig 9: Locking Connector Lock Button Connects
  Courtesy 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 10: Disconnecting Connectors
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
7. Improper connection prevention lock mechanism:
  When connecting the holder, the lever is pushed into the end by rotating around the A axis to lock the holder securely.
  
  Fig 11: Connecting Holder
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

DISCONNECTION OF CONNECTORS FOR HORN BUTTON ASSY, FRONT PASSENGER AIRBAG ASSY (SQUIB SIDE), CURTAIN SHIELD AIRBAG ASSY AND INSTRUMENT PANEL AIRBAG ASSY LOWER NO.1
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 12: Inserting Screwdriver Tip Between Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
CONNECTION OF CONNECTORS FOR HORN BUTTON ASSY, FRONT PASSENGER AIRBAG ASSY (SQUIB SIDE), CURTAIN SHIELD AIRBAG ASSY AND INSTRUMENT PANEL AIRBAG ASSY LOWER NO.1
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 13: Pushing Down Securely On Lock Button (Yellow Part) Of Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
DISCONNECTION OF CONNECTOR FOR FRONT PASSENGER AIRBAG ASSY (INSTRUMENT PANEL WIRE SIDE)
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 Disconnecting Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
CONNECTION OF CONNECTOR FOR FRONT PASSENGER AIRBAG ASSY (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 15: Connecting Slider
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
DISCONNECTION OF CONNECTOR FOR FRONT SEAT AIRBAG ASSY
1. Place a finger on the slider, slide the slider to release the lock, and then disconnect the connector.
  
  Fig 16: Placing Finger On Slider
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
CONNECTION OF CONNECTOR FOR FRONT SEAT AIRBAG ASSY
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 17: Connecting Slider
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
DISCONNECTION OF CONNECTOR FOR AIRBAG SENSOR ASSY CENTER
1. Pull the lever by pushing part A as shown in the illustration and disconnect the holder (with connectors).
  
  Fig 18: Pulling Lever By Pushing Part
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  HINT:
  
  Perform the following procedures when replacing the holder.
2. Remove the holder.
  1. Using a screwdriver, unlock the retainer.
    
    Fig 19: Removing Holder Using Screwdriver
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. Release the fitting lance and remove the holder.
    
    Fig 20: Removing Connectors To Holder
    Courtesy 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.
  
  Fig 21: Installing Connectors To Holder
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
CONNECTION OF CONNECTOR FOR AIRBAG SENSOR ASSY CENTER
1. Firmly insert the holder (with connectors) into the airbag sensor assy center until it cannot be pushed any further.
2. Push the lever to connect the holder (with connectors). (When locking, a click sound can be heard.)
  HINT:
  
  The holder slides in to the airbag sensor assy center when it is being connected. Be sure not to hold the holder while connecting, as it may result in an insecure fit.
  
  Fig 22: Connecting Connectors To Holder
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
DISCONNECTION OF CONNECTOR FOR AIRBAG SENSOR FRONT
1. Push down the housing lock (white part) and slide the CPA (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 23: Pushing Down Housing Lock
  Courtesy 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 24: Positioning Of Housing Lock Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
CONNECTION OF CONNECTOR FOR AIRBAG SENSOR FRONT
1. Before connecting the connectors, check that the position of the housing lock (white part) is as shown in the illustration.
  
  Fig 25: Connecting Of Connector For Airbag Sensor Front
  Courtesy 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 A part, as it may result in an insecure fit.
  
  Fig 26: Connecting Housing Lock
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
DISCONNECTION OF CONNECTORS FOR SIDE airbag SENSOR ASSY AND AIRBAG SENSOR REAR
1. While holding both the sides of the outer connector locking sleeve, slide the outer in the direction shown by the arrow.
2. When the connector lock is released, the connectors are disconnected.
  HINT:
  
  Be sure to hold both outer flank sides. Holding the top and bottom will make disconnection difficult.
  
  Fig 27: Disconnecting Of Connectors For Side airbag Sensor
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 28: Connecting Of Connectors For Side airbag Sensor
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
CONNECTION OF CONNECTORS FOR SIDE AIRBAG SENSOR ASSY AND AIRBAG SENSOR REAR
1. Connect the connector as shown in the illustration. (When locking, make sure that the outer returns to its original position and a click sound can be heard.)
  HINT:
  
  When connecting, the outer will slide. Be sure not to hold the outer while connecting, as it may result in an insecure fit.
  
  Fig 29: Connecting Of Connectors
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002