Toyota Camry 2007-2009 Service Manual - SRS

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

AIRBAG SYSTEM

PRECAUTION

CAUTION:

• The vehicle is equipped with a Supplemental Restraint System (SRS). It consists of a driver airbag, front passenger airbag, driver side knee airbag, side airbag, curtain shield airbag, and front seat belt pretensioner. 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 foll ow the correct procedures indicate d 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 if work is started within 90 seconds after disconnecting the negative (-) terminal cable from the battery, the SRS may be deployed.)

• Do not expose the steering pad, front passenger airbag assembly, driver side knee airbag assembly, center airbag sensor assembly, front airbag sensor, front seat inner belt assembly, seat position airbag sensor, occupant classification ECU, front seat side airbag assembly, side airbag sensor, curtain shield airbag assembly, rear airbag sensor, or front seat outer belt assembly directly to hot air or flames.

NOTICE:

• 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 steering pad, front passenger airbag assembly, driver side knee airbag assembly, center airbag sensor assembly, front airbag sensor, front seat inner belt assembly, seat position airbag sensor, occupant classification ECU, front seat side airbag assembly, side airbag sensor, curtain shield airbag assembly, rear airbag sensor, or front seat outer belt assembly should be inspected.

• Before repair work, remove the airbag sensor if any kind of shock is likely to occur to the airbag sensor during the operation.

• Never use SRS parts from another vehicle. When replacing parts, replace them with new ones.

RS–1

RS–2

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

• Never disassemble or repair any of the following p art s 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. (a)Steering Pad (b)Front Passenger Airbag Assembly (c)Driver Side Knee Airbag Assembly (d)Front Seat Side Airbag Assembly (e)Curtain Shield Airbag Assembly (f) Center Airbag Sensor Assembly (g)Front Airbag Sensor (h)Front Seat Inner Belt Assembly (i) Seat Position Airbag Sensor (j) Occupant Classification ECU (k)Side Airbag Sensor (l) Rear Airbag Sensor (m)Front Seat Outer Belt Assembly

• Use an 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 page RS-32).

• 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, refer to the precaution in the INTRODUCTION section.

HINT: In the airbag system, the center airbag sensor assembly , front airbag sensor LH and RH, side airbag sensor LH and RH, and rear 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 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).

(b) When connecting or disconnecting the airbag

sensor connectors, ensure that each sensor is installed in the vehicle.

dropped during the operation or transportation.

(d) Do not disassemble the airbag sensors.

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

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. 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.

Expression

Ignition Switch off LOCK Off Ignition Switch on (IG) ON On (IG) Ignition Switch on (ACC) ACC On (ACC) Engine Start START Start

Ignition Switch (position) Engine Switch (condition)

Switch Type

RS–3

RS–4

Driver Side:

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

4. SRS CONNECTORS

(a) SRS connectors are located as shown in the

following illustration.

Center Airbag Sensor Assembly

Combination Meter Assembly (SRS Warning Light)

Driver Side Knee Airbag Assembly (Driver Side Knee Airbag Squib)

Steering Pad (Driver Side Squib)

Front Airbag Sensor LH

Side Airbag Sensor LH

Rear Airbag Sensor LH

Spiral Cable

16 15

1 2

3 4

Front Seat Side Airbag Assembly LH (Driver Side - Side Squib)

Curtain Shield Airbag Assembly LH (Driver Side Curtain Shield Squib)

Front Seat Outer Belt Assembly LH (Driver Side Front Pretensioner Squib)

Front Seat Inner Belt Assembly LH (Driver Side Seat Belt Buckle Switch) / Seat Position Airbag Sensor

C123769E01

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

Passenger Side:

Center Airbag Sensor Assembly

RS–5

1 2

3 4

31 32

Occupant Classification ECU

Front Seat Side Airbag Assembly RH (Front Passenger Side - Side Squib)

Curtain Shield Airbag Assembly RH (Front Passenger Side Curtain Shield Squib)

Front Seat Outer Belt Assembly RH (Front Passenger Side Front Pretensioner Squib)

Side Airbag Sensor RH

Rear Airbag Sensor RH

109

Front Passenger Airbag Assembly (Front Passenger Side Squib)

15 16

Front Airbag Sensor RH

Clock Assembly (Passenger Airbag ON/OFF Indicator)

No. Item Application

(1) Terminal Twin-Lock Mechanism Connectors 5, 6, 9, 10, 15, 16, 20, 22, 23, 24, 31, 32 (2) Activation Prevention Mechanism Connectors 2, 4, 5, 10, 11, 13, 23, 25, 27 (3) Half Connection Prevention Mechanism Connectors 5, 6, 9, 16, 20, 22, 24

C123770E01

RS–6

No. Item Application

(4) Connector Position Assurance Mechanism Connector 18 (5) Connector Lock Mechanism (1) Connectors 8, 12, 14, 26, 28 (6) Connector Lock Mechanism (2) Connector 2, 4 (7) Improper Connection Prevention Lock Mechanism Connector 1, 3

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

(b) All connectors in the SRS, except the seat position

airbag sensor connector, are colored yellow to distinguish them from other connectors. These

Spacer

connectors have special functions, and are specially designed for the SRS. All SRS connectors use durable gold-plated terminals, and are placed in the

Housing

locations shown on the previous page to ensure high reliability.

MaleFemale

Z005953E02

(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.

Housing

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

(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.

●When Connector is Connected ●When Connector is Disconnected

Short Spring Plate

Contacting Male Terminal

RS–7

Terminal

Connectors

Locking Part

Housing

Squib

Short Spring Plate

Stopper

Locking Arm

Slider

Short Spring Plate ON

Squib

Closed Circuit

(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.

Spring

Rebound by Slider (Spring)

Stopper

H045309E03

H040180E07

RS–8

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

(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.

Housing Lock (White Part)

CPA (Yellow Part)

H043306E02

(5) Connector lock mechanism (1):

Locking the connector lock button connects the connector securely.

Lock Button

Claw

Groove

H040181E04

Lance

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

(6) Connector lock mechanism (2):

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

Holder

RS–9

Retainer

H043918E01

(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.

Lever

H043245E01

RS–10

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

5. DISCONNECTION OF CONNECTORS FOR STEERING PAD, FRONT PASSENGER AIRBAG ASSEMBLY (SQUIB SIDE), DRIVER SIDE KNEE AIRBAG ASSEMBLY, CURTAIN SHIELD AIRBAG ASSEMBLY, AND FRONT SEAT OUTER BELT ASSEMBLY

HINT: Tape up 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.

Lock Button (Yellow part)

Ta pe

Mark

Lock Button (Yellow part)

C123672E01

6. CONNECTION OF CONNECTORS FOR STEERING PAD, FRONT PASSENGER AIRBAG ASSEMBLY (SQUIB SIDE), DRIVER SIDE KNEE AIRBAG ASSEMBLY, CURTAIN SHIELD AIRBAG ASSEMBLY, AND FRONT SEAT OUTER BELT ASSEMBLY

(a) Connect the connector.

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

(b) Push down securely on the lock button (yellow part)

of the connector. (When locking, a click sound can be heard.)

Lock Button (Yellow part)

7. DISCONNECTION OF CONNECTOR FOR SPIRAL CABLE (INSTRUMENT PANEL WIRE SIDE) AND FRONT PASSENGER AIRBAG ASSEMBLY (INSTRUMENT PANEL WIRE SIDE)

(a) Place a finger on the slider, slide the slider to

release the lock, and then disconnect the connector.

RS–11

H043151E04

Slider Slider

Disconnection is completed

H001586E02

RS–12

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

8. CONNECTION OF CONNECTOR FOR SPIRAL CABLE (INSTRUMENT PANEL WIRE SIDE) AND FRONT PASSENGER AIRBAG ASSEMBLY (INSTRUMENT PANEL WIRE SIDE)

(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.

Slider

Connection is completed

H043731E02

9. DISCONNECTION OF CONNECTORS FOR FRONT SEAT SIDE AIRBAG ASSEMBLY

(a) Place a finger on the slider, slide the slider to

release the lock, and then disconnect the connector.

Slider

Disconnection is completed

H001584E03

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

10. CONNECTION OF CONNECTORS FOR FRONT SEAT SIDE AIRBAG ASSEMBLY

(a) Connect the connector as shown in the illustration.

Slider

RS–13

Connection is completed

H043169E02

11. DISCONNECTION OF CONNECTOR FOR CENTER AIRBAG SENSOR ASSEMBLY

(a) Pull the lever by pushing part A as shown in the

illustration and disconnect the holder (with

connectors).

Holder (with connectors)

Disconnection is completed

H045112E01

HINT: Perform the following procedures when replacing the holder.

RS–14

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

(b) Remove the holder.

(1) Using a screwdriver, unlock the retainer.

Retainer

H043188E01

(2) Release the fitting lance and remove the holder.

Lances

H043190E01

H043189E01

(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.

12. CONNECTION OF CONNECTOR FOR CENTER AIRBAG SENSOR ASSEMBLY

(a) Firmly insert the holder (with connectors) into the

center airbag sensor assembly until it cannot be pushed any further.

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

Holder (with connectors)

RS–15

(b) 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 assembly when it is being connected. Be sure not to hold the holder while connecting, as it may result in an insecure fit.

Lever

Connection is completed

H045113E01

13. DISCONNECTION OF CONNECTOR FOR FRONT 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.

RS–16

Connector lock is released

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

Housing Lock (White Part)

CPA (Yellow Part)

H043302E02

position of the housing lock (white part) is as shown in the illustration.

H043303E02

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

14. CONNECTION OF CONNECTOR FOR FRONT AIRBAG SENSOR

(a) Before connecting the connectors, check that the

position of the housing lock (white part) is as shown in the illustration.

RS–17

H043304E01

CPA (Yellow Part)

(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.

Housing Lock (White Part)

Connection is completed

H043305E02

RS–18

Outer

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

H002763E02

Connector lock is released

15. DISCONNECTION OF CONNECTORS FOR SIDE AIRBAG SENSOR AND REAR AIRBAG SENSOR

(a) While holding the sides of the outer connector

locking sleeve, slide the outer in the direction shown by the arrow.

(b) 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.

Disconnection is completed

H002764E02

16. CONNECTION OF CONNECTORS FOR SIDE AIRBAG SENSOR AND REAR AIRBAG SENSOR

(a) 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.

Outer

Connection is completed

H002768E02

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

PARTS LOCATION

RS–19

REAR AIRBAG SENSOR

FRONT SEAT SIDE AIRBAG ASSEMBLY

SIDE AIRBAG SENSOR

FRONT SEAT SIDE AIRBAG ASSEMBLY

REAR AIRBAG SENSOR

SIDE AIRBAG SENSOR

FRONT AIRBAG SENSOR

SEAT POSITION SENSOR

FRONT SEAT INNER BELT ASSEMBLY LH

OCCUPANT CLASSIFICATION ECU

C123718E02

RS–20

COMBINATION METER ASSEMBLY: CLOCK ASSEMBLY:

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

SRS WARNING LIGHT

CURTAIN SHIELD AIRBAG ASSEMBLY

PASSENGER AIRBAG ON/OFF INDICATOR

FRONT PASSENGER AIRBAG ASSEMBLY

CURTAIN SHIELD AIRBAG ASSEMBLY

FRONT SEAT OUTER BELT ASSEMBLY RH

DRIVER SIDE KNEE AIRBAG ASSEMBLY

SPIRAL CABLE

STEERING PAD

CENTER AIRBAG SENSOR ASSEMBLY

FRONT SEAT OUTER BELT ASSEMBLY LH

C123719E01

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

SYSTEM DIAGRAM

RS–21

Front Airbag Sensor LH

Front Airbag Sensor RH

Side Airbag Sensor LH

Side Airbag Sensor RH

Rear Airbag Sensor LH

Rear Airbag Sensor RH

Steering Pad (Driver Side Squib)

Front Passenger Airbag Assembly (Front Passenger Side Squib)

Driver Side Knee Airbag Assembly (Driver Side Knee Airbag Squib)

Front Seat Side Airbag Assembly LH (Driver Side - Side Squib)

Front Seat Side Airbag Assembly RH (Front Passenger Side

- Side Squib)

Curtain Shield Airbag Assembly LH (Driver Side Curtain Shield Squib)

Seat Position Airbag Sensor

Front Seat Inner Belt Assembly LH (Driver Side Seat Belt Buckle Switch LH)

Occupant Classification ECU

: CAN

Curtain Shield Airbag Assembly RH (Front Passenger Side Curtain Shield Squib)

Front Seat Outer Belt Assembly LH (Driver Side Front Pretensioner Squib)

Front Seat Outer Belt Assembly RH (Front Passenger Side Front Pretensioner Squib)

Clock Assembly (Passenger Airbag ON/OFF Indicator)

C123736E01

RS–22

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

ECM

Main Body ECU

Combination Meter Assembly

DLC3

: CAN

C123737E01

Transmitting ECU

(Transmitter)

Center Airbag Sensor Assembly ECM Crash detection signal Center Airbag Sensor Assembly Main Body ECU Driver seat buckle switch signal

Center Airbag Sensor Assembly Combination Meter Assembly

Combination Meter Assembly Center Airbag Sensor Assembly

ECM Center Airbag Sensor Assembly

Receiving ECU Signals Communication method

• SRS warning light ON demand signal

• SRS warning light blink demand signal

• Passenger seat occupant detection signal

• Passenger seat buckle switch signal

• Diagnosis signal (DTC)

• Vehicle speed signal

• Meter diagnoses polling signal

• Engine speed signal

• Accelerator opening angle information

• Accelerator opening angle signal

• Shift position signal

• Test mode signal

• Stop signal

CAN

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

SYSTEM DESCRIPTION

1. GENERAL

(a) In conjunction with impact absorbing structure for a

front collision, the SRS (Supplemental Restraint System) driver airbag, front passenger airbag, and driver side knee airbag were designed to supplement seat belts in the event of a front collision in order to help reduce shock to the head and chest of the driver and front passenger and knee of the driver. This system is a 3-sensor type airbag system to detect the impact during a front collision using the center airbag sensor assembly and front airbag sensors. It also operates the airbag system and seat belt pretensioner.

(b) In order to detect the extent of the collision during

the initial stages of the collision in further details, the front airbag sensors have been changed from mechanical type to electrical type deceleration sensors. Accordingly, the deployment of the driver airbag and front passenger airbag is controlled in two stages according to the severity of the impact.

side collision, the side airbag and curtain shield airbag were designed to help reduce shock to the driver, front passenger, and rear outer passengers in the event of a side collision.

(d) The curtain shield airbag that helps reduce shock to

the front and rear seat occupants with a single curtain shield airbag has been adopted. In conjunction with this system, the side airbag sensors have been installed at the bottom of the center pillars and the rear airbag sensors have been installed at the bottom of the rear pillars.

(e) In this system, a front side collision is detected by

the side airbag sensor in order to simultaneously deploy the side and curtain shield airbags. A rear side collision is detected by the rear airbag sensor and the center airbag sensor assembly in order to deploy the curtain shield airbag.

(f) The center airbag sensor assembly sends the

airbag deployment signal to the ECM through CAN (Controller Area Network) to operate the fuel pump control.

2. CONSTRUCTION AND OPERATION

(a) FRONT AIRBAG SENSOR

(1) The front airbag sensors are installed on the

right and left radiator supports respectively.

(2) The front airbag sensor consists of the

deceleration sensor.

RS–23

RS–24

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

(3) The deceleration sensor is built into the front

airbag sensor, and the distortion that is created in the sensor is converted into an electric signal based on the vehicle deceleration rate during a frontal collision. Accordingly, the extent of the initial collision can be detected in detail.

(b) SIDE AIRBAG SENSOR

(1) The side airbag sensors are installed on the

bottom of the right and left center pillars respectively.

(2) The side airbag sensor consists of the

deceleration sensor and ignition control circuit.

(3) The deceleration sensor is built into the side

airbag sensor, and the distortion that is created in the sensor is converted into an electric signal based on the vehicle deceleration rate during a front side collision. Accordingly, the extent of the initial collision can be detected in detail.

(1) The rear airbag sensors are installed on the right

and left rear pillars respectively.

(2) The rear airbag sensor consists of the

deceleration sensor and ignition control circuit.

(3) The deceleration sensor is built into the rear

airbag sensor, and the distortion that is created in the sensor is converted into an electric signal based on the vehicle deceleration rate during a rear side collision. Accordingly, the extent of the initial collision can be detected in detail.

(d) CENTER AIRBAG SENSOR ASSEMBLY

(1) General

• The center airbag sensor assembly is installed on the center floor under the instrument panel.

• The center airbag sensor assembly consists of the deceleration sensor, safing sensor, electronic safing sensor, ignition control circuit, and diagnostic circuit.

• The center airbag sensor assembly receives signals from the deceleration sensor and safing sensor built into the center airbag sensor assembly and front airbag sensor. Then the center airbag sensor assembly determines whether the driver airbag, front passenger airbag, driver side knee airbag, and front seat belt pretensioners should be activated, and diagnoses system malfunctions.

• The center airbag sensor assembly causes the front seat side airbag assembly and the curtain shield airbag assembly to deploy when receiving signals from the side airbag sensor.

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

• The center airbag sensor assembly receives signals from the deceleration sensor and the electronic safing sensor built into the center airbag sensor assembly and the rear airbag sensor, and determines whether the curtain shield airbag should be activated, and diagnoses system malfunctions.

• The center airbag sensor assembly sends the airbag deployment signal to the ECM through CAN to operate the fuel pump control.

(2) Deceleration sensor and ignition control circuit

• The deceleration sensor is built into the center airbag sensor assembly.

• The ignition control circuit performs calculations based on the signal output from the deceleration sensors of the center airbag sensor assembly and front airbag sensor. If the calculated values are greater than the specified values, it activates ignition operation.

(3) Safing sensor

• The safing sensor is built into the center airbag sensor assembly. During a front collision, the sensor turns on and outputs an ON signal to the center airbag sensor assembly if a deceleration rate sent to the safing sensor is greater than the specified value.

(4) Electronic safing sensor

• The electronic safing sensor is built into the center airbag sensor assembly. During a side collision, the sensor turns on and outputs an ON signal to the center airbag sensor assembly if a deceleration rate sent to the electronic safing sensor is greater than the specified value.

(5) Backup power source

• The backup power source consists of a power supply capacitor and a DC-DC converter. When the power system does not function during a collision, the power supply capacitor discharges and supplies electric power to the system. The DC-DC converter operates as a boosting transformer when the battery voltage falls below a predetermined level.

(6) Diagnostic circuit

• This circuit constantly diagnoses system malfunctions. When a malfunction is detected, it turns on the SRS warning light on the combination meter assembly to inform the driver.

RS–25

RS–26

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

(7) Memory circuit

• When a malfunction is detected in the diagnostic circuit, it is coded and stored in the memory circuit.

(e) SRS WARNING LIGHT

(1) The SRS warning light is located on the

combination meter assembly. It comes on to inform the driver of system trouble when a malfunction is detected in self-diagnosis of the center airbag sensor assembly. Under normal operating conditions when the ignition switch is turned on (IG), it comes on for approximately 6 seconds and then goes off.

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

Center Airbag Sensor Assembly

RS–27

3. DEPLOYMENT CONDITION

When the vehicle collides and the shock is greater than the specified value, the SRS is activated automatically. The center airbag sensor assembly includes the safing sensor and deceleration sensor. The safing sensor is designed to turn on at a smaller deceleration rate than the deceleration sensor. (a) The center airbag sensor assembly determines

whether ignition is necessary based on signals from the deceleration sensor and the front airbag sensor (*1). If the safing sensor turns on simultaneously, current flows to the squibs to deploy the SRS as shown in the illustration below.

Steering Pad

Safing Sensor ON

Deceleration Sensor ON

Center Airbag Sensor Assembly

Safing Sensor ON

Deceleration Sensor ON

Front Airbag Sensor (*1)

AND

Front Passenger Airbag Assembly

Driver Side Knee Airbag Assembly

Front Seat Outer Belt Assembly

Steering Pad

Front Passenger Airbag Assembly

Driver Side Knee Airbag Assembly

Front Seat Outer Belt Assembly

C109526E05

HINT: *1: In case of front collision, the ignition signal could be output with the deceleration sensor ON signal even without a signal from the front airbag sensor.

RS–28

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

(b) The center airbag sensor assembly determines

whether ignition is necessary based on signals from the side airbag sensor. If the safing sensor turns on simultaneously, current flows to the squib to deploy the SRS as shown in the illustration below.

Center Airbag Sensor Assembly

Safing Sensor

Front Seat Side Airbag Assembly

AND

Curtain Shield Airbag Assembly

Side Airbag Sensor

Front Seat Side Airbag Assembly Deployment

Safing Sensor

Center Airbag Sensor Assembly

Rear Airbag Sensor (*1)

whether ignition is necessary based on signals from the rear airbag sensor. If the safing sensor turns on simultaneously, current flows to the squib to deploy the SRS as shown in the illustration below (*1).

AND

Curtain Shield Airbag Assembly

C109527E12

C109528E03

HINT: *1: If the front seat side airbag assembly deploys, the curtain shield airbag assembly will also deploy, regardless of whether the signal is output from the rear airbag sensor.

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

HOW TO PROCEED WITH TROUBLESHOOTING

The intelligent tester can be used in steps 3, 5, 7, 9, and 10.

VEHICLE BROUGHT TO WORKSHOP

CUSTOMER PROBLEM ANALYSIS

(a) Confirm problem symptoms (See page IN-45).

CHECK CAN COMMUNICATION SYSTEM

(a) Check for DTC outputs.

HINT: The center airbag sensor assembly is connected to the CAN communication system. Therefore, before starting troubleshooting, make sure to check that there is no trouble in the CAN communication system.

Result

CAN communication DTC is not output. A CAN communication DTC is output. B

RS–29

Result Proceed To

WARNING LIGHT CHECK

CHECK DTC (Present and Past DTCs)

(a) Check for DTC outputs.

Result

DTC is output. A DTC is not output. B

INSPECT CAN COMMUNICATION CIRCUIT

Result Proceed To

PROBLEM SYMPTOMS TABLE

RS–30

SUPPLEMENTAL RESTRAINT SYSTEM – AIRBAG SYSTEM

DTC CHART

CIRCUIT INSPECTION

REPAIR

CLEAR DTC (Present and Past DTCs)

END

CHECK DTC (Present and Past DTCs)

CONFIRMATION TEST

(a) Check for DTC outputs.

Result

Result Proceed To

DTC is not output. A DTC is output. B

Go to step 6

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Toyota Camry 2007-2009 Service Manual - SRS

Specifications and Main Features

Frequently Asked Questions

User Manual