Steering wheel buttons intermittently not working

[Germgh0st]

So something strange has happened to my 2019 W205 C43. All of the buttons on the steering wheel work fine apart from 2 on the right hand side - the little touch panel button and the back arrow button. It's only these two, and every now and then they will work OK.

The only thing I can think that causes weird things like this is a failing battery, but before I spend £150 odd on one does anyone have any better ideas?

 

[Jobsworth]

I have replaced a couple of switch packs. Try giving it a little clean first. In my experience those tend to be the most used of the buttons on the block

 

[Germgh0st]

How do the switch blocks come out? Does the steering wheel need to come apart? Absolutely no idea where I'd get replacements, half an hour of Googling gives me nothing which kind of indicates a dealer

 

[Jobsworth]

Airbag out, then you can access screws that hold the gearshift paddles in. Once paddles are out you can get to screws for switch block

 

[Germgh0st]

Seems the switch blocks only come as a pair, £155 from MB. I think I might be a bit concerned about getting the airbag out, the way my luck goes it'll go off in my face or something.... But thanks for the info

 

[Benz17]

I replaced the airbag on my W213 myself, I just disconnected the battery before doing so, no problems whatsoever.

 

[zipdip]

Yes disconnect the battery and wait to be on the saafe side at least 20 mins,plenty of how too's on the net,not a vast amount of tools needed but if you do not generally do repairs to your car then maybe let a indy do it.

 

[Jobsworth]

It won’t go off in your face. You’d have to apply 12v and an earth directly onto two very small pins, which for safety have contacts which drop over to short them the moment their plug is removed. It would take a very concerted effort to set one off deliberately. Accidentally, never!

 

[Germgh0st]

So little update. I discovered that if I fully charged the battery then the buttons work. But after a bit of driving and stops and starts they stop again.

So I had a new battery fitted because the car sits on my drive most of the week as I work from home and after 4 years of that I suspected the battery might be on it's way out.

After having the new battery fitted the buttons worked again for a while but have now stopped.

So I have the car booked in with my (fortunately) very local indy at the start of next year to see if they can figure out out the problem.

As additional information - the stop/start only works when the buttons are working. All seems to be pointing at some sort of electrical / battery issue.