Supplemental Restraint System (Diagnostics - Introduction): Other Toyota Matrix E140

PRECAUTION

HINT

1. In the airbag system, the center airbag sensor assembly, front airbag sensors LH and RH, side airbag sensors LH and RH, and rear airbag sensors LH and RH are collectively referred to as the airbag sensors. The steering pad, front passenger airbag assembly, front seat side airbag assembly, curtain shield airbag assembly, center airbag sensor assembly, front airbag sensor, side airbag sensor, rear airbag sensor, seat position airbag sensor, front seat inner belt assembly, front seat outer belt assembly or occupant classification ECU are collectively referred to as the SRS parts.

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 that does not cause the SRS to deploy, the SRS parts should be inspected. Before beginning repairs, remove the airbag sensors if any kind of shock is likely to occur to the airbag sensors during the operation. Never use SRS parts from another vehicle. When replacing parts, replace them with new ones. Never disassemble or repair any of the SRS parts in order to reuse them. If any of these parts have been dropped, or any defect is found (e.g. cracks, dents or any other defects) in any of the housings, brackets or connectors, replace the part with a new one. Use a volt/ohmmeter with high impedance (10 kohms/V minimum) for troubleshooting the electrical circuits. Information labels are attached near the SRS parts. Follow the instructions noted in the caution. After work on the SRS is completed, perform an SRS warning light check. Refer to DIAGNOSIS SYSTEM . When the cable is disconnected from the negative (-) battery terminal, the memory will be cleared. Therefore, be sure to make a record of the contents memorized in each system before starting work. When work is finished, adjust each system to its previous state. Never use a backup power supply for the purpose of retaining the memory of vehicle electronic systems. If the vehicle is equipped with a mobile communication system, refer to the precautions in the INTRODUCTION information.

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1. HANDLING PRECAUTIONS FOR AIRBAG SENSORS Before starting the following operations, wait for at least 90 seconds after disconnecting the cable from the negative (-) battery terminal: Replacement of the airbag sensors Adjustment of the front/rear doors of a vehicle equipped with the front seat side airbags and curtain shield airbags (fitting adjustment) When connecting or disconnecting the airbag sensor connectors, ensure that each sensor is installed in the vehicle. Do not use airbag sensors which have been dropped. Do not disassemble the airbag sensors.
2. INSPECTION PROCEDURE FOR VEHICLE INVOLVED IN ACCIDENT If any of the airbags have not deployed, confirm the DTCs by checking the SRS warning light. If there is any malfunction in the SRS airbag system, perform troubleshooting. If any of the airbags have deployed, replace the airbag sensors and check the installation condition.
3. FUNCTION OF SRS CONNECTORS SRS connectors are located as shown in the following illustration. No. Connector Type Application (1) Terminal Twin-Lock Mechanism Connectors 5, 6, 9, 10, 13, 14, 18, 20 (2) Activation Prevention Mechanism Connectors 2, 4, 5, 7, 9, 11, 25, 27, 29 (3) Half Connection Prevention Mechanism Connectors 6, 10, 13, 18, 20 (4) Connector Position Assurance Mechanism Connectors 16, 26 (5) Connector Lock Mechanism (1) Connectors 8, 12, 28, 30 (6) Connector Lock Mechanism (2) Connectors 2, 4 (7) Improper Connection Prevention Lock Mechanism Connectors 1, 3 Connectors in the SRS 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. 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. 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. Half connection prevention mechanism: If the connector is not completely connected, the connector is disconnected due to the spring force so that no continuity exists. Connector position assurance mechanism: Only when the housing lock (white part) is completely engaged, the CPA (yellow part) slides, which completes the connector engagement. Connector lock mechanism (1): Locking the connector lock button connects the connector securely. Connector lock mechanism (2): Both the primary lock with holder lances and the secondary lock with a retainer prevent the connectors from becoming disconnected. Improper connection prevention lock mechanism: When the holder is connected, the lever is pushed into the end by rotating around the A axis to lock the holder securely.
4. DISCONNECTION OF CONNECTORS FOR STEERING PAD, FRONT PASSENGER AIRBAG ASSEMBLY (SQUIB SIDE), CURTAIN SHIELD AIRBAG ASSEMBLY, AND FRONT SEAT OUTER BELT ASSEMBLY HINT: Tape the screwdriver tip before use. Release the lock button (yellow part) of the connector using a screwdriver. 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 ASSEMBLY (SQUIB SIDE), CURTAIN SHIELD AIRBAG ASSEMBLY, AND FRONT SEAT OUTER BELT ASSEMBLY Connect the connector. Push down securely on the lock button (yellow part) of the connector. When locked, a click sound can be heard.
6. DISCONNECTION OF CONNECTOR FOR SPIRAL CABLE (INSTRUMENT PANEL WIRE SIDE) Slide the slider to release the lock, and then disconnect the connector.
7. CONNECTION OF CONNECTOR FOR SPIRAL CABLE (INSTRUMENT PANEL WIRE SIDE) 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 the connector is connected, the slider will slide. Be sure not to touch the slider while connecting, as it may result in an insecure fit.
8. DISCONNECTION OF CONNECTOR FOR CENTER AIRBAG SENSOR ASSEMBLY Pull the lever by pushing part A as shown in the illustration and disconnect the holder (with connectors). HINT: Perform the following procedures when replacing the holder. Remove the holder. Using a screwdriver, unlock the retainer. Release the fitting lance and remove the holder. Install the holder. Install the connectors to the holder. When locked, a click sound can be heard. HINT: The retainer is locked when the holder is connected.
9. CONNECTION OF CONNECTOR FOR CENTER AIRBAG SENSOR ASSEMBLY Firmly insert the holder (with connectors) into the center airbag sensor assembly until it cannot be pushed any further. Push the lever to connect the holder (with connectors). When locked, 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.
10. DISCONNECTION OF CONNECTORS FOR FRONT AIRBAG SENSOR AND FRONT SEAT SIDE AIRBAG ASSEMBLY Push down the housing lock (white part) and slide the CPA (yellow part). At this time, the connector cannot be disconnected yet. Push down the housing lock (white part) again and disconnect the connector. HINT: Do not push down part A shown in the illustration when disconnecting. 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 AND FRONT SEAT SIDE AIRBAG ASSEMBLY Before connecting the connectors, check that the position of the housing lock (white part) is as shown in the illustration. Be sure to engage the connectors until they are locked. When locking, make sure that a click sound can be heard. HINT: When engaged, the housing lock (white part) will slide. Be sure not to hold the housing lock (white part) and part A, as it may result in an insecure fit.
12. DISCONNECTION OF CONNECTORS FOR SIDE AIRBAG SENSOR AND REAR AIRBAG SENSOR While holding the sides of the outer connector locking sleeve, slide the sleeve in the direction shown by the arrow. When the connector lock is released, the connectors can be disconnected. HINT: Be sure to hold both sides. Holding the top and bottom will make disconnection difficult.
13. CONNECTION OF CONNECTORS FOR SIDE AIRBAG SENSOR AND REAR AIRBAG SENSOR Connect the connector as shown in the illustration. When locking, make sure that the sleeve returns to its original position and a click sound can be heard. HINT: When the connector is connected, the sleeve will slide. Be sure not to hold the sleeve while connecting, as it may result in an insecure fit.

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1. GENERAL FRONTAL COLLISION The driver airbag and front passenger airbag are designed to supplement seat belts in the event of a frontal collision in order to help reduce shock to the head and chest. A frontal collision is detected by the center airbag sensor and two front airbag sensors. The driver airbag, front passenger airbag and seat belt pretensioners then operate simultaneously. SIDE COLLISION The front seat side airbags and curtain shield airbags are designed to help reduce shock to the driver, front passenger and rear outer passengers in the event of a side collision. A side collision is detected by the side airbag sensor installed in the bottom of the center pillar and the rear airbag sensor installed in the bottom of the rear pillar. A front side collision is detected by the side airbag sensor, causing the front seat side airbag and curtain shield airbag to deploy simultaneously. A rear side collision is detected by the rear airbag sensor, causing only the curtain shield airbag to deploy.
2. CONSTRUCTION AND OPERATION FRONT AIRBAG SENSOR The front airbag sensors are installed on the right and left radiator supports respectively. Each front airbag sensor uses an electrical type deceleration sensor. The deceleration sensor is built into each 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. SIDE AIRBAG SENSOR The side airbag sensors are installed on the bottom of the right and left center pillars respectively. Each side airbag sensor uses an electrical type deceleration sensor. The deceleration sensor is built into each 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. REAR AIRBAG SENSOR The rear airbag sensors are installed on the right and left rear pillars respectively. Each rear airbag sensor uses an electrical type deceleration sensor. The deceleration sensor is built into each 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. CENTER AIRBAG SENSOR General The center airbag sensor is installed on the center floor under the instrument panel. The center airbag sensor consists of a deceleration sensor, safing sensor, ignition control circuit, and diagnostic circuit, etc. The center airbag sensor receives signals from the deceleration sensor and safing sensor built into the center airbag sensor and front airbag sensor, and determines whether the driver airbag, front passenger airbag, and front seat belt pretensioner should be activated. In addition, the center airbag sensor diagnoses system malfunctions. The center airbag sensor receives signals from the deceleration sensor and the safing sensor built into the center airbag sensor, the side airbag sensor and the rear airbag sensor, and determines whether the front seat side airbag and the curtain shield airbag should be activated. In addition, the center airbag sensor diagnoses system malfunctions. The center airbag sensor sends the airbag deployment signal to the ECM through CAN (Controller Area Network) to operate the fuel pump control. Deceleration sensor and ignition control circuit The deceleration sensor is built into the center airbag sensor, front airbag sensors, side airbag sensors and rear airbag sensors, and the distortion created based on the deceleration of the vehicle during a frontal, side or rear collision is converted into an electric signal. The ignition control circuit performs calculations based on the signal output from the deceleration sensors of the center airbag sensor, front airbag sensors, side airbag sensors and rear airbag sensors. If the calculated values are greater than the specified values, an ignition operation will be initiated. Safing sensor The safing sensor is built into the center airbag sensor. When a frontal, side or rear collision occurs, the corresponding sensor turns on and outputs an ON signal to the center airbag sensor if the deceleration rate sent to the safing sensor is greater than the specified value. 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. 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. Memory circuit When a malfunction is detected in the diagnostic circuit, it is coded and stored in the memory circuit. SRS WARNING LIGHT 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. Under normal operating conditions, when the ignition switch is turned to ON, the warning light comes on for approximately 6 seconds and then goes off.
3. DEPLOYMENT CONDITION If 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 lower deceleration rate than the deceleration sensor. 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. HINT: *1: In case of a frontal collision, the ignition signal could be output with the deceleration sensor ON signal even without a signal from the front airbag sensor. 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. The center airbag sensor assembly determines 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. 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.

CHECK MODE PROCEDURE

1. CHECK MODE (SIGNAL CHECK): DTC CHECK Turn the ignition switch off. Connect the Techstream to the DLC3. Turn the ignition switch to ON and turn the Techstream on. Enter the following menus: Body Electrical / SRS Airbag / Utility / Signal Check. Select Signal Check, and proceed with checking using the Techstream. NOTE: Select Signal Check from the Trouble Code screen displayed on the Techstream to clear the output DTCs (both present and past). HINT: DTCs can be detected more sensitively in check mode than in a normal diagnosis. Perform check mode inspection when a malfunction in each squib circuit is suspected even after the normal system code is output through a normal diagnosis inspection.