Turbo hoses are
Join Date: Nov 2013
Location: United Kingdom
County: West Sussex
To be clear, the airbag light IS an MOT failure. An MOT station is not going to investigate the cause of anything, it will pass it or fail it, not attempt to diagnose or fix it. In your case, ARNovice (possibly your garage does your repairs as well as your MOT...?), I suspect they chose to 'ignore' it, because they can see it's a duff light rather than a duff airbag! It is a fail, your car should not pass the test if ANY warning lights are active on the dashboard. It is totally nanny-state, don't-they-realise-my-car-is-Italian, EU bureaucrat-led-nonsense but it is the rule!
Mine passed... but only once i'd prised out the display with a screwdriver (I broke the surround unfortunately, so be careful), got the top screen off and covered it with insulating tape before putting it all back together. Light's still on, but nobody can see it. Luckily, it doesn't show as an info centre error on start-up so nobody is any the wiser. My wife's 307 has the same fault, and it beeps AIRBAG FAULT for the first 10 seconds after start-up. Faulty sensor - £350 to fix at a pug main dealer. But £350 is mere pocket change to spend on a car, as we all know... :-)
Go screwdrivers and tape on this one pal, can't go wrong...! My 156 has bad sensors under the drivers seat which cause mine to go off - seeing as yours is a 3 door, maybe movement raising/lowering the drivers seat is doing the damage?