Air Bag Systems: Service Precautions

AIRBAG SYSTEM

PRECAUTION

CAUTION:
- The vehicle is equipped with a Supplemental Restraint System (SRS), which consists of a steering pad, front passenger airbag, driver side knee airbag, passenger side knee airbag, front seat side airbag, seat belt pretensioner, center airbag sensor, front airbag sensor, side airbag sensor, door side 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 ignition 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 ignition 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 repair work, remove airbag sensors as necessary if any kind of impact is likely to occur to an airbag sensor during the operation.
- 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 kohms/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.
- 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.
- When disconnecting the cable from the negative (-) battery terminal, initialize the following system(s) after the cable is reconnected.
- Front Power Seat Control System
- Meter / Gauge System

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

1. HANDLING PRECAUTIONS FOR AIRBAG SENSORS

a. Before starting the following operations, wait for at least 90 seconds after disconnecting the cable from the negative (-) terminal of the battery:

1. Replacement of the airbag sensors.
2. Adjustment of the front / rear doors of the vehicle equipped with the side airbag (fitting adjustment).

b. When connecting or disconnecting the airbag sensor connectors, ensure that each sensor is installed in the vehicle.
c. Do not use an airbag sensor which has been dropped during the operation or transportation.
d. Do not disassemble the airbag sensors.

2. INSPECTION PROCEDURE FOR VEHICLE INVOLVED IN ACCIDENT

a. 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.
b. When any of the airbags have deployed, replace the airbag sensors and check the installation condition.

3. SRS CONNECTORS

a. SRS connectors are located as shown in the following illustration.

b. 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 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.

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.

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.

5. Connector lock mechanism(1): Locking the connector lock button connects the connector securely.

6. Connector lock mechanism (2): Both the primary lock with holder lances and the secondary lock with retainer prevent the connectors from becoming disconnected.

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.

4. DISCONNECTION OF CONNECTORS FOR STEERING PAD, FRONT PASSENGER AIRBAG (SQUIB SIDE) AND FRONT SEAT OUTER BELT

HINT: Tape the screwdriver tip before use.

a. Release the lock button (yellow part) of the connector using a screwdriver.

b. Insert the screwdriver tip between the connector and the base, and then raise the connector.

5. CONNECTION OF CONNECTORS FOR STEERING PAD, FRONT PASSENGER AIRBAG (SQUIB SIDE) AND FRONT SEAT OUTER BELT

a. Connect the connector.

b. Push down securely on the lock button (yellow part) of the connector. (When locking, a click sound can be heard.

6. DISCONNECTION OF CONNECTOR FOR FRONT PASSENGER AIRBAG (INSTRUMENT PANEL WIRE SIDE)

a. Place a finger on the slider, slide the slider to release the lock, and then disconnect the connector.

7. CONNECTION OF CONNECTOR FOR FRONT PASSENGER AIRBAG (INSTRUMENT PANEL WIRE SIDE)

a. Place a finger on the slider, slide the slider to release the lock, and then disconnect the connector.

9. CONNECTION OF CONNECTORS FOR FRONT SEAT AIRBAG

a. 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.

10. DISCONNECTION OF CONNECTOR FOR FRONT AIRBAG SENSOR, DOOR SIDE AIRBAG SENSOR AND SIDE AIRBAG SENSOR

a. Push down the housing lock (white part) and slide the CPA (yellow part). (At this time, the connector cannot be disconnected yet.)

b. 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.

c. After disconnecting the connector, check that the position of the housing lock (white part) is as shown in the illustration.

11. CONNECTION OF CONNECTOR FOR FRONT AIRBAG SENSOR, DOOR SIDE AIRBAG SENSOR AND SIDE AIRBAG SENSOR

a. Before connecting the connectors, check that the position of the housing lock (white part) is as shown in the illustration.

b. 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.