01221 airbag light on

[mike777]

Hi

Have searched the forums and not quite sure how to proceed. Airbag light was on intermittently a few times but now stuck on. Get the 01221 error code side crash sensor - wiring.
Have checked the wiring under the seat and it seems fine so looking at checking the sensor itself but some people say it's in the door some in the door pillar, anyone know which?
Or any other ideas?

1.8t 2002

Thanks