My car flew through the MOT last week. Booked the Aygo in for 14th Feb to check air bag - mentioned it to the guy doing the MOT's and he said 'I just finished your MOT, jumped in the car and the airbag light went on, I cleared it and it came back'. I said, 'It will be the driver's seat'. Popped home, unzipped seat back, unclipped airbag connector, cleaned contacts, plugged in diagnostics, cleared code, and voila, all gone'.
I've still been doing checks on the Aygo. Pulled the connections to the air bag control module, cleaned re-assembled. Light went out again, but came back after a couple of drives. Didn't think more about it, as my reader has been refusing to connect. Ran a couple of questions past the Toyota forum, and one suggested pulling the connectors on the module and re-scanning. I'd not re-scanned. Bingo, connected last night and pulled the code. "Steering Squib/clockring'. Sorted. Used part ordered (30 day guarantee) and should be here tomorrow.
Re-scanned again last night, "nah, I'm not talking to you". If the replacement part works, I'll cancel the garage visit.