I recently went on a track day, and towards the end of the session (thankfully) my friend who was driving manged to hit one of the rumble strips quite hard, at this point there was a big 'explosion' on his side of the car and the seat belt locked up.

I presumed it to be the seat belt tensioner, as it would not retract into the 'B' pillar. After about an hour it seemed to reset itself and the seat belt runs freely into and out of the 'B' pillar as normal.

Is my theory of the tensioner correct do you think, if it is do I have to get this reset at all? If so, any idea of a rough cost of this?

Next time we go on the track in my car, I have told him to be a little less aggressive and try not to break my car again.

Your thoughts and suggestions would be welcomed please.

John

The ones we replace at BMW have be replaced if they've gone off. Never heard of resetting them. HTH.

When the seat belt pre-tensioner fires off the base part that the belt plugs into re-tracts itself and pulls the belt tight to the body. I dont see that this would affect its retraction back into the B post at all. If you can acess it to view it you can tell if it has gone off as it has a tube where the steel wire/cable slides along as it is fired off. I havent ever closely inspected this on a VAG vehicle, but I have had experiance of these on french cars and you can tell when the tensioner has been fired.

Lewwy