Damn seat belt sensor!!!

Just after Christmas the car throws a code warning about the passanger seat airbag not working and that the passanger should wear a seat belt because of this. Bring it to the dealer and was told the sensor for the airbag deployment was in the seat belt buckle. Dropped the car off and got a 2013 Burnt Orange X1 (quite the vagina-mobile!). All covered under CPO

After replacing one side, they called me ti inform that they will do the drivers side as well. Damn part is coming from Vancouver (freight because they couldnt air ship it because something in the buckle was classifed as an explosive... WTF!) lol. Now Im told Friday, maybe Monday.

I lost my car for 1 week for a damn seatbelt buckle!!!! Only a BMW! haha

Originally Posted by greco2000

After replacing one side, they called me ti inform that they will do the drivers side as well. Damn part is coming from Vancouver (freight because they couldnt air ship it because something in the buckle was classifed as an explosive... WTF!) lol. Now Im told Friday, maybe Monday.

I lost my car for 1 week for a damn seatbelt buckle!!!! Only a BMW! haha

I like the exploding seatbelt buckle angle. Are you driving James Bond's Astin Martin?

The seat-belt tensioners are actually pyro devices like airbags. Note the black canister in the pic:

It's a bit strange that BOTH pre-tensioners would fail at the same time, I'd question the reason for that.
It is worth noting that it is normally the seat occupancy sensor built in to the seat (a webbing) that fails first, I'd just double check that the correct component is being replaced. The webbing inside the sat base detects when somebody is sitting on the seat, this web can break over time, especially if someone were to kneel on the seat. Is it a BMW franchise or independent specialist that is providing the diagnosis? I'm not saying your pre-tensioner would not fail, it can, but given that the diagnosis provided suggested that both have failed would make me suspicious that the diagnosis might be incorrect.

Also, seat belts & airbag are not strictly an "either or" solution. It's an integrated solution (MRS) where the airbag works in tandem with you wearing the seat belt, a bit disconcerting to see that you'd only wear the seat belt if there was an airbag light illuminated. The pre-tensioner in the seat belt buckle (the pyro) pulls the seat belt tighter to take up the slack in the seat belt when a crash sensor detects an impact. It is deployed at the same (assuming the be
belt is fastened).
US market cars (I presume Canada gets "US Market" configured cars) seem to have a "half way house" type deployment solution where the airbag would be deployed without the belt fastened. However this is less than optimal safety protection

Here's an explanation on how the Multiple Restraint System (MRS) works, this article is for an e38 but the principle is the same:
http://www.meeknet.co.uk/e38/E38_Air...ystem_MRS4.pdf

This was all done at a bmw dealership. Problem was only one side, but to do me a favour, they replaced both sides. It all covered under warranty, so I couldn't care less.

nice to see they covered everything and gave you a driveable loaner car.

I had the seat belt buckle/sensor/tensor component go out on my daughter's ten-year old Acura with 187k miles - the dealer replaced it under a "lifetime" warranty on the seat belt safety system. First time I'd ever heard of a lifetime warranty on a car component.

Originally Posted by greco2000

This was all done at a bmw dealership. Problem was only one side, but to do me a favour, they replaced both sides. It all covered under warranty, so I couldn't care less.

Ah right, that's fair enough so. I just was saying it in case you were getting charged for unnecessary work. Best of luck!

The pyro charge in the tensioners are awesome.