seat belt restraint detonators

[boblydon]

Just been reading different items on the internet regarding the explosive charges inside the the seat belt restraints (on the seats)....if following an accident and there detonated....how do you know ??? do the seat belts not lock anymore ?? does it illuminate the airbag/srs light or the seatbelt light ??.

How can you test them, are they open/closed circuit or work on a resistive value.

In a normal state prior to operating would they be open or closed circuit.

Regards

Bob

 

[markjay]

I don't know, but I would have thought that these will be tested by the SRS ECU on engine ignition and the SRS fault light illuminate if not in working order.

The restraint is crucial as it pulls the occupant back to reduce injury from the inflating airbag, so if not operational then SRS ECU should know about it and disable the airbags.

 

[boblydon]

Thanks for the reply, i would agree with what your saying as they are a safety item.

Just re read my post, it was the seat belt pretensioner stalks i was meaning, sorry i did not make that clear in my post.

Bob

 

[thecolonel]

the car will be smashed up, so normally a good tell tale!
they dont go off in minor knocks and when they do, its to prevent the seat belt from moving forward before the inertia units jam shut - so they resist against forward motion. Once deployed if the car is still operable, there will be an SRS light on along with a host of other units warning of issues.
Seat belts will still lock perfectly well, but there will be bits of airbag, dashboard and alike floating around so not a fun place to sit anymore.

I have never seen them deploy before except in a major accident when the car has had a major impact.