OBD2 — The Current Standard
In 1994, CARB mandated by regulation that all new motor vehicles from 1996 onwards must contain the newly developed OBD2 system. This would utilize a standardized interface allowing one OBD scanner to be used for different car manufacturers.

There are four different types of OBD-II codes – P, B, C, and U. The P stands for powertrain (engine and transmission) systems, B for body, C for chassis, and U for network and wiring systems. If the ECU commands the check engine light to illuminate, there will always be at least one P0 code stored.

OBD-II codes, or trouble codes, tell you specifically what's wrong with your car – from the transmission to the ignition, to brakes and airbags. An OBD-II code reader is an electronic device that plugs into your vehicle's OBD-II port, usually located under the steering column.

First character (P, C, B, or U). This character indicates the system associated with the fault.
Second character (0-9). Specifies the specific fault within the system.
Third and fourth characters (0-9). Provide additional information about the fault's location or nature.
Fifth character (0-9).

Probably the most reliable and recommended method to reset the airbag light is to use a diagnostic tool or an OBD scanner. These tools can communicate with your vehicles control units, read error codes, and reset the airbag light once the issue is resolved.