Operation CHARM: Car repair manuals for everyone.

Construction




A: GENERAL
The SRS airbag consists of an airbag control module, electric sensor and safety sensor built into the control module, and airbag modules of driver and passenger containing an inflator and airbag. Electric sensor and safely sensor are connected in series, so that the airbag will inflate if electric sensor and safety sensor sense an impact at the same time.




B: AIRBAG CONTROL MODULE
The airbag control module is installed ahead of the front floor tunnel. It detects the vehicle's deceleration by receiving electrical signals from the sensors and judges whether to fire the airbag. This control module has a built-in self-diagnosis function. If a trouble occurs inside the system, it lights up the airbag warning light in the combination meter. The trouble data is stored in the module. A back-up power supply is provided for possible damage to the battery during an accident, and a boosting circuit is built into the module in case of a battery voltage drop.




C: SAFETY SENSOR AND ELECTRIC SENSOR
Safety sensor and electric sensor are built into the airbag control module.

Safety sensor is the pendulum type sensor. If the sensor receives a frontal impact exceeding a certain limit, the mass in the sensor revolves forward to turn the switch ON.

Electric sensor consists of the semiconductor type sensor which senses the deceleration at collision by the change of the electrical resistance and the impact sensing circuit.




D: AIRBAG MODULE
The driver's airbag module is located at the center of the steering wheel, and passenger's airbag module is located at upper side of instrument panel, and it each contains an airbag and inflater. If a collision occurs, the inflator produces a large volume of nitrogen gas inflating the nylon airbag in a very short time.

E: AIRBAG CONNECTOR
The SRS airbag adopts a connector which has a double lock mechanism and coupling error detection mechanism for enhanced reliability. If coupling is incomplete, the airbag warning light comes on in the combination meter.




1. CONNECTOR COUPLED TO AIRBAG CONTROL MODULE
To disconnect the connector, press wire (1) of the control unit as illustrated below until the green lever (2) tilts up. This unlocks the double lock, then you can pull off the connector while pressing tile connector lock.

To couple the connector, insert the three connectors until a "click" is heard, then push in the green lever (2) to apply the double lock.




2. CONNECTOR BETWEEN HARNESSES
To disconnect the connector, press lever (1) to pop green lever (2) out, this unlocks the double lock system. Then separate the connector by pulling both sides while holding the connector sections and pressing in lever (1).

To couple the connector, insert both connectors until a "click" is heard, then push in the green lever (2) until a "click" is heard; this applies the double lock.




F: STEERING ROLL CONNECTOR
The steering roll connector is located between the steering column and steering wheel. A flat cable stored in a spiral form transmits the electrical signal from the airbag control module to the steering wheel from the body harness.




G: AIRBAG WARNING LIGHT
The airbag warning light is located inside the combination meter. It illuminates if a poor connection occurs, or if the airbag control module detects an abnormality, When the airbag system is normal, this light goes out about 7 seconds after turning the ignition switch ON.

H: WIRE HARNESS
The wire harness of the SRS airbag is entirely covered with a yellow protective tube, and can easily be identified from harnesses of other systems.