Resetting service warning lights

Only an idiot would want to power equipment through a 1 Megohm resistor.

You don't have a clue.

Note that I have no direct experience with air bag control systems - its possible they are all designed by muppets with no safety critical embedded system design nous, but I am going to guess not! (most of the safety critical things "that can go bang" I have worked on were typically parts of systems that were designed to kill you!)

However, the design philosophy with control systems in charge of potentially lethal hardware will take the approach that you have to work hard to actually activate and fire it. If anything fails in the software, then it can't fire. If the hardware detects a fault, then it can't be activated and so on. Then there must be redundant hardware so that there are multiple interlocks, to prevent failure of any one part defeating the interlocks.

Which should just mean it can't activate it.

Although I've never worked on "defence" systems, I have worked on process control, so ...

Although all this is true, cars are savagely "engineered" down to a cost and I wouldn't be at all surprised to find that much of this has been omitted. After all, consider the various scandals concerning automative safety over the years, e.g.;

I'd be prepared to wager that the manufacturers have balanced the cost of spurious activations against the cost of enhanced engineering. But then, car mechanics are notoriously ham-fisted!

BTW, this looks interesting, and I shall file it away for future reading (who am I kidding?);

Reluctant as I am to intrude into other people's arguments the obvious example here surely, is seatbelts.

In vehicles which were originally manufactured and supplied without seatbelts - classic and vintage cars etc then theres no requirement to wear a seatbelt. The only limitation is a prohibition on carrying children under the age of 3 years old in such vehicles.

This even applies to models where welding suitable mounting points wouldn't present much of a problem. As is sometimes done by owners who maybe prioritise safety, and possibly lower insurance premiums over total period authenticity.

michael adams

...

Surely it's time we banned these death-traps?

Quite. If airbags really were so 'touchy' there would be countless stories about them going off when a car was having welding done. etc. Or rocked by the wind - which sets off so many alarms.

There, fixed it for you.

But not always fully, it seems. 12V appears to be the expected voltage. I'm not sure what explosive they use inside these bags; I'd guess lead azide or something similar 'cos something like mercury fulminate would be too unstable. And do they only need a primer, or a secondary propellant as well? It would be interesting to know how they're initially fired when that 12V is applied.

Looks like it. Why persist in feeding this troll?

He posted some pretty substantial Act in its entirety rather than citing the relevant section he's depending on and expects everyone to wade through it all just to find his bit - if it even exists (and one would think if it did he would have cited it properly).

Of course there are plenty of news reports that claim the airbag went off for no good reason so I expect my view is more correct than yours, but who knows?

For example..

Plenty more on google.

"Pass me the airbag light timing sequence book" said no MOT tester, ever!

I ran an MX5 for a number of years with such an setup.

That actually has some interesting bits.. like...

For a change you are correct, they haven't passed the date yet, but by April 2019 they should have.

I have told you look for them yourself and you might learn something. Have you bothered to find the two posts that have the links in them that you claim to have missed? I'm not going to do it for you so either do so or shut up moaning about it.

You still have 4V at the end of it, are you saying it won't fire an airbag now or still saying it will? As I said before the voltage is fairly irrelevant but you disagree, do you want to explain why or just keep on with cr@p comments.

Lead azide would get you sued by every crash victim. You are probably thinking..

You can thank huge for that.

Its obviously is to you as you keep saying 4V will set it off when its the energy that matters not the voltage.

automotive. You are very welcome.

Are you ever going to contribute something useful in this group or just keep trolling? I don't think you have ever posted something useful here or anywhere else. Are you huge by another name? Maybe you are jws or Australian?