Some 1991 Accord models are equipped with SRS (often called an air bag). The airbag is located directly inside the steering wheel hub; sensors and control unit - behind the dashboard. The airbag helps during frontal collisions and complements the functions of the seat belt system. It is not effective if the seat belts are not fastened.
An air bag is a fabric bag with an attached explosive inflation device. The system uses two shock sensors, a hood sensor, as well as a pumping circuit and a control unit. The backup power system is connected in parallel with the battery. None of the sensors by itself can trigger the protection system, this requires almost simultaneous (within 0.002 sec) operation of at least two sensors - a hood sensor located in the center under the dashboard, and one of the shock sensors located on the left and right front under the feet.
When the control unit receives two such signals, power is supplied to the pumping circuit (or from a backup system - or from a battery). A small heater causes a chemical reaction in the igniter; non-poisonous gas from a chemical mixture very quickly (within milliseconds) expands to fill the bag and pull it through the decorative steering wheel cover. Since everything happens very quickly, the expanding bag must reach the driver before the driver hits the steering column during a frontal collision. By the time the pillow is fully inflated, the chemical reaction is already over; just press down on the pad and the gas will slowly escape through the outlets behind the bag.
The control unit contains a self-diagnosis circuit. After turning the ignition key to position "ON" The system warning light should come on and go out after about 6 seconds. If the lamp does not light up, does not go out, or lights up already while driving, the system should be diagnosed and repaired by a Honda dealer. The home airbag system is NOT repairable.