See Figure 1
Some late model Subaru vehicles are equipped with an air bag system, to supplement the safety belts. When an impact at the front of the vehicle is greater than a set level in the air bag sensor, the sensor senses it and generates an electrical pulse to inflate the bag in the air bag module, preventing the drivers body from contacting the steering wheel.
The SRS air bag consists of an control unit, left and right front sensors, 2 safety sensors built into the control unit and an air bag module containing an air bag and inflator. The left and right front sensors and the 2 safety sensors are connected in parallel respectively, and the front sensors and safety sensors are connected in series, so the air bag will inflate if at least 1 front sensor and 1 safety sensor sense an impact at the same time.
The components of the SRS system are not owner serviceable and no attempts should be made to repair the system, however, when working on any of the electrical systems inside of the vehicle, the air bag system must be disarmed. This can be accomplished by following the disarming procedure given in this section.
All SRS electrical wiring harnesses and connections are covered with yellow outer insulation.
See Figures 2, 3 and 4
The SRS is designed to deploy the air bag when the safing sensor and any of the 4 sensors (front crash zone sensor, center crash zone sensor, left crash zone sensor or tunnel sensor) simultaneously make contact, with the ignition switch in the ON position. Air bag deployment will occur in a frontal or near frontal impact of moderate to severe force.
The diagnostic unit monitors the SRS system and stores data, should any faults be detected in the system. When the engine is started or the ignition switch is in the ON or START position, the SRS warning light should illuminate for approximately 7 seconds and then turn OFF. This indicates that the system is operational.
See Figure 5
The air bag module, located in the center of the steering wheel, contains a folded air bag and an inflator unit.Spiral Cable
The spiral cable, located in the steering column, ensures an uninterrupted electrical circuit to the air bag module, while allowing rotation of the steering wheel. This cable is sometimes referred to as a clockspring.Warning Lamp
The warning lamp, located in the instrument panel, indicates operational status of the SRS.SRS Control Unit
The SRS control unit, monitors the SRS system and stores data, should any faults be detected in the system.Air Bag Connector
The SRS system connectors use a double lock mechanism and a coupling error detection system. If the connector is not properly connected, the air bag warning light will illuminate on the instrument cluster.
The proper method for using these connectors is to press the release tab on the connector until the green lever pops up, this will unlock the connector. Then pull the connector apart while pushing the lever down. To reconnect the connectors, push the halves together until a click is heard then push the green lever down until another click is heard.
DISARMING THE SYSTEM
See Figures 6, 7 and 8
Be sure to properly disconnect and connect the air bag connector.
- Turn the ignition switch to the OFF position.
- Disconnect the negative battery cable.
- Remove the lower lid from the steering column and disconnect the harness between the air bag module and spiral cable.
ENABLING THE SYSTEM
- Reconnect the connector between the air bag module and spiral cable. Then install the lower steering column lid.
- Reconnect the negative battery cable.
- Turn the ignition switch to the ON position and observe the SRS warning light. The SRS warning light should illuminate for approximately 7 seconds, turn OFF and remain OFF for at least 45 seconds.
- If the SRS warning light function as indicated in Step 3, the SRS system is functioning properly.