Do I need to disconnect battery?

[clk320x]

I need to change the front acceleration/pedestrian detection sensor on my W212 as I have an active bonnet error on dash and STAR has diagnosed this sensor as being at fault. I have ordered the part from Merc.

It's easy enough to get to, remove front grill and there's one bolt holding it in. Just unplug it and disconnect the bolt.

However on the WIS document it mentions disconnecting the battery? I really don't want to be faffing around resetting windows etc, can anyone think of why this might be needed? Surely if the engine is switched off, swapping out this sensor shouldn't be an issue?

Cheers.

 

[clk320x]

Anyone? Part will be here soon

 

[bob6600]

Theoretically, it should be fine as it's the sensor. Leave it for a few minutes and let the car go to 'sleep' and don't open any doors etc.

If it is anything like airbags though, it's worth disconnecting as it may trigger it off and then for the hassle of resetting the windows you will wish you had done it properly lol.

 

[AMGeed]

As above, I doubt it makes any difference, but to be sure, why not just remove the neg battery lead. It only takes a minute to reset all the windows.

 

[pmcgsmurf]

Agree with others, unlikely to be a problem but belt and braces to just disconnect.

 

[clk320x]

Thanks guys, I suppose the worst thing that can happen is the active bonnet will get set off... hmm... tbh I have no clue where the battery even is is it in the boot on these or in the engine bay?

 

[Edd1968]

....its battery is in my shed Abs. It doesn't have one!!

 

[Edd1968]

I've do e so many similar jobs without disconnecting the battery. Abs. Let the car go to sleep and just change it.

 

[thebiglad]

With ANY modern car if you want to avoid trouble, disconnect the battery - if you like living on the edge, don't.

 

[PobodY]

I've do e so many similar jobs without disconnecting the battery. Abs. Let the car go to sleep and just change it.

I fiddle with the SRS stuff without disconnecting the battery, but make damn sure the ignition is off first so it can't wake up and get upset.

 

[clk320x]

I fiddle with the SRS stuff without disconnecting the battery, but make damn sure the ignition is off first so it can't wake up and get upset.

So close the doors, and give it 5 mins or so? I guess I can’t lock the doors with the key with the bonnet open as it won’t like that?​

 

[Benzmanc]

The battery should be under an airbox on the passenger side, under the bonnet up by the winscreen

 

[Edd1968]

I fiddle with the SRS stuff without disconnecting the battery, but make damn sure the ignition is off first so it can't wake up and get upset.

Me too, whipped off the steering wheels (including disconnecting airbags) on various cars, never had one go off yet!
They won't as they're not designed to go off under those conditions. Its a H&S thing these days.