when your passenger airbag light is burned out, the system senses a loss of continuity, and proceeds to warn you of the failure, with a 5 set series of 5 dings. Enough to make you mental.
I went to the dealer for the part ( dealer only ) and decided that I would rather play pick up sticks with my butt cheeks, than pay what they wanted for the airbag switch.
I took it apart, and found what was required for a bulb. Picked one up at radio shack, carefully soldered it in, and problem solved. just like that. I can't recall the number of the bulb that I got, only that they come in packages of two. For about $3 CDN. so if you are strapped, a couple of you could get together, and float $1.50 each..... anyway.
That is how I fixed the problem.