Some 1991 Accord models are equipped with the Supplemental Restraint System (SRS) (often referred to as an air bag). The air bag 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 belts are not fastened.
The air bag is a fabric bag with an attached explosive inflation device. The system uses two impact sensors, a bonnet sensor, as well as an inflation circuit and a control unit. The backup power supply system is connected in parallel with the battery. None of the sensors by themselves can trigger the protection system; this requires the almost simultaneous (within 0.002 sec) activation of at least two sensors - the bonnet sensor, located in the center under the dashboard, and one of the impact sensors located on the left and right in front under the feet.
When the control unit receives two such signals, power is supplied to the pumping circuit (either from the backup system - or from the battery). A small heater causes a chemical reaction in the igniter; the non-toxic gas from the chemical mixture expands very quickly (within milliseconds), filling the bag and drawing it through the decorative steering wheel cover. Because everything happens so quickly, the expanding bag should reach the driver before the driver hits the steering column during a frontal collision. By the time the bag is fully inflated, the chemical reaction is already complete; simply press on the cushion and the gas will begin to slowly escape through the outlet holes behind the bag.
The control unit contains a self-diagnostic circuit. After turning the ignition key to the "ON" position, the system warning lamp should light and go out after about 6 seconds. If the lamp does not light, does not go out, or lights up while driving, the system should be diagnosed and repaired at a Honda dealership. The airbag system is NOT repairable at home.