I just recently repaired my tach, and as such had my gauge cluster out. I fired up the car as such, and drove to work to solder the board, and once everything was repaired and re-installed I noticed my airbag light was illuminated. At first I disconnected the battery for a few minutes to see if that would clear the code. No such luck. I found two methods to reset this light. And as usual by following this, or anything mentioned in this writeup, you are assuming all risks to yourself, your vehicle, and anything related.
1 - Construct a little gadget/tool for between $5-$10, or
2 - Follow the Big Green Book(BGB).
I chose the BGB as it was free and a lot faster than fabricating a small electric switch. So, after following steps from the BGB I determined it was a code 41, which is a code that is stored in memory and cannot be removed by disrupting the power source to the car. I followed the instructions in the BGB, below, to clear this code with success.
Some things to note before doing this: To clear the code 41 the written instructions in the BGB list terminals Te and AB on the diagnosis port, whereas the diagram shows terminals Tc and AB. This was misleading and gave me some trouble at first. I had success following the instructions, but instead of using terminals Te and AB(as per the written instructions) to clear code 41, I used the terminals Tc and AB as per the diagram.
The diagnosis port is located here, circled in yellow, and has a grey flip top with the pins/ports labeled on the underside of the flip top.
The BGB references a special service tool(SST) to connect the terminals. A paperclip or a length of wire will suffice.
To clear code 41 I used longer lengths of wire that made it easy for me to ground the terminal. By grounding the terminal you are simply taking the wire that is plugged into the terminal and touching the exposed end to a source of ground on the frame of the car. In my case I used one of the bolts securing the suspension near the diagnosis box. Basically you will tap the one terminal, beginning with Tc to the bolt(ground), hold for approximately 1 second, then remove and very quickly tap the wire from the other terminal to the bolt(ground), hold for approximately 1 second and remove, repeat again for both, and on the third time you ground Tc you will not remove it(this is the last step). You will hold the wire grounding terminal Tc to the bolt until the airbag light begins to flash rapidly(it may take a few seconds for this to occur).
It might take a few tries to get the rhythm right, and from what I've read online this method is referred to as "playing the drums"...lol. Please keep in mind that if your airbag light is illuminated because of an actual fault in your system, that clearing the light will not work as the fault will cause the light to come on again. Please properly diagnose why your light is on before attempting to clear the code.