Loud bang, smoke - Help !!

[no46]

I have a 5 y/o C220 D - Got into it there and put key in ignition and there was a huge bang and a small amount of smoke appeared in the interior. Since then there has been a 'sulphur' type smell and I have no power whatsoever. The display mentioned something about the restraint deploying (this has since gone). I figure this may have something to do with the passenger side airbag detonator going off - but that is a guess.

Can anyone offer any advice on this please.

 

[anyweb]

very odd,

did anything bang the car while it was parked ? I don't know the exact mechanism for what provokes an airbag to fill, but surely if one was deployed you'd see it hanging there with no air in it (they defalte immediately).

use your nose and sniff around the car in the dashboard area both sides to see can you locate the source of the smell, in addition, do you see anything on the instrument panel when you turn the key ?

 

[Pookis Dad]

At a guess I would think this is linked with the seat belt anchorage which use pyrotechnics to fire the "tightening" sequence of a belt.

Check them for signs of shortening (i.e. one being lower than the other) and perhaps cracks or splits in the plastic covers of the anchorages.

As for lack of power, it is possibly linked to the firing of the pyrotecnics or perhaps a short caused the problem.

I wonder if it has triggered a limp home mode sequence in the ecu?

 

[no46]

The airbag itself has not detonated (at least visibly) I suspect it may have been the detonator for the airbag. The smoke appeared mostly at the passenger side. my son noticed some liquid on the ground just behind the passenger side front wheel arch.

 

[no46]

At a guess I would think this is linked with the seat belt anchorage which use pyrotechnics to fire the "tightening" sequence of a belt.

Check them for signs of shortening (i.e. one being lower than the other) and perhaps cracks or splits in the plastic covers of the anchorages.

As for lack of power, it is possibly linked to the firing of the pyrotecnics or perhaps a short caused the problem.

I wonder if it has triggered a limp home mode sequence in the ecu?

Will check that as best as I can - I now zero about motors what do you mean by limp home sequence in the ecu ?

 

[Blobcat]

Another option (if your car has them) could be seat belt pre-tensioners.
As this will have stored a fault code it maybe worth getting the fault codes read if you cannot find what has failed.

 

[Blobcat]

Will check that as best as I can - I now zero about motors what do you mean by limp home sequence in the ecu ?

Is the car running and driving as normal. If the car thinks something is wrong it can go into a limp home mode which is basically reduced power.

 

[no46]

There is no power at all.

The display reads 'restraint system visit workshop - SRS'

 

[Blobcat]

I think you may want to follow that advice then.

Who normally does the servicing on your car?

 

[no46]

I think you may want to follow that advice then.

Who normally does the servicing on your car?

The only time I have had it serviced (I have not had it that long) it was done by a local independent Merc guy. I rang him and he was puzzled and suggested that it may be airbag related.

Problem is it is an automatic with no power at all.

 

[Pookis Dad]

The "no power" bit threw me.

Do you mean electrical power? As in, the engine won't crank, the lights don't come on, or the engine goes, but the gears won't engage?

I am not a Merc bloke, but most cars are generic and Mercedes lead the way with technological breakthroughs which other manufacturers copy.

Another possible cause of the smell is a dead short across the battery terminals has caused the battery to explode (rare, but it happens). That would also lead to a sulphur smell and no power.

 

[no46]

No power as in no lights and no engine crank.

Still get the little warning lights in the console display but no lights, indicators etc.

Also the airbag off light is illluminated.

 

[Pookis Dad]

I'm afraid my lack of knowlege about the marque means I am of little use to you, but I wonder if this model has either two batteries or a back up battery to keep vital memories alive?

I would check the main battery first.

A few years ago, a colleague of mine managed to place the jump leads on a good battery. Easy enough, except the leads were home made and he put the negative ends on the battery terminals.

Result?

Bang, exploded battery and no juice.

Fairly certain your car will have a back up battery for memory, but I could be wrong.

 

[anyweb]

good idea, get or buy a new battery and test it., if the car works i'd still get it checked out, as the smell/bang/smoke is not a good sign no matter what, as the battery is in your boot (at least it is on mine) and therefore how would you get the smell in the passenger side front (along with the liquid) ?

 

[Daggle]

The battery is located on the passenger side under a large plastic piece of ducting. Mercedes have been changing some batteries that were made in South Africa because they have been bursting or exploding. Most of the batteries seem to be fitted to the E class but a dealer may well have re-used one of the faulty ones on your car.

 

[no46]

The battery is located on the passenger side under a large plastic piece of ducting. Mercedes have been changing some batteries that were made in South Africa because they have been bursting or exploding. Most of the batteries seem to be fitted to the E class but a dealer may well have re-used one of the faulty ones on your car.

Removed the ducting cover and the battery indeed appears to have exploded the plastic casing around the battery has shattered and there is damage to the underside of the casing that houses the battery. I assume that a new battery will be all that is required to get me up and running again?

 

[anyweb]

hopefully !

perhaps it could even be covered by mercedes, check with your dealer

cheers

anyweb

 

[Ultymate]

The contents of your battery is acid and will quickly damage anything it comes in contact with ie upholstery/paintwork etc you need to dilute it with water as quickly as possible