A small aside to the previous post, when I reattached the battery to test the horn with the airbag assembly still off the car’s computer registered the missing airbag as a fault. When I got everything back together and started the car my SRS light stayed lit. I was confident that my airbag was fine, so I figured I needed to reset the light. Thanks to a post on swedishbricks.net I learned how to do it, and I’ll share it here too.
The first step it to locate the SRS diagnostic port. On my car this is located on the center console between the switches for the rear defroster and the hazard lights. There is a small panel with SRS on it. Using a small screwdriver or your fingernail you can easily lift that cover off.
Next make a little jumper wire. One end will go into the contact of the diagnostic port. That’s the metal bit towards the top in my photo. I used a paperclip that I unbent and stuck that into the port. Then I used a short jumper wire with alligator clips at either end and clipped one end to the clip. I only used this wire because I had it around from a time when I made it to jumper the fuel pumps at the fuse box, but any wire about three inches long will work.
Before we clear the code we should see what the computer thought the problem was. To do this, turn on the ignition without starting the car. The dashboard warning lights should turn on as normal. Wait about 15 seconds and then ground the free end of the wire by touching it to the ring of the cigarette lighter plug. hold it there for two seconds. After contact is broken the SRS light will flash a few times and then flash one to ten times. This is the fault code that was causing the light to stay on. In my case I saw five flashes which indicated that the computer detected too high of an electrical resistance to my airbag. Since my airbag was disconnected and thus the resistance was effectively infinite this makes sense. A list of all the codes can be found here.
To clear the codes you will need to perform a timed sequence of events. Touch the jumper wire three times for at least 0.25 seconds within 1.5 to 5 seconds. Once you get it right the light will go out for four seconds, come back on for three, and then turn off for good.