After the Airbag light tripped on my 98 328i I diagnosed the problem, which was a defective passenger seat occupancy sensor. Naturally I ordered a replacement, but could not bear looking at that annoying light on the cluster every time I drive the car over the next 3 - 4 weeks until the repalcement sensor arrives.
Resetting the SRS/Airbag system was not an option as it immediately re-tripped due to the defective sensor still being in circuit.
After a bit of digging I found this link and built the little circuit, which I then soldered to the leads cut from the defective sensor (I used a 1N4004 diode as I didn't have a 1N4001 on hand). Viola ! the airbag light now works as it should.
I thought that I would post this as I know others have similar problems (the downside is that BOTH airbags will trip if one is deployed, regardless of whether the passenger seat is occupied until the sensor is replaced).