Thanks for the advice, MRS. I'm hoping to get the brake fault diagnosed either today or on Monday at either Bosch or Mercedes. My understanding is that as it has been recalled and the original unit replaced, it should revert to a "normal" (non electronically-assisted) braking system if it fails and be safe to drive. There is also apparently a use-count trigger, which would seem likely on a vehicle with the miles mine has. The error is just that, not a warning, so I'll still drive it (carefully) until it is fixed.

I'll take a look at the rear wiper, but the car has only been in sunny climes for 6 months, so the previous ten years may have rendered your tip too late!

You don't happen to know where the fuse is for the phone cradle, do you? I can't find reference to it anywhere...

Is the rear wiper motor still working, Jim? If it is, I'd oil the shaft liberally for a few days with a very light/penetrating oil to stop any corrosion that might be there. Then apply grease to seal.

No - I don't know where it is. Are all the fuses in the main fuse centre ok?

The rear wiper works, I'll stick some WD40 down it! I think I've got some silicon grease somewhere too. Thanks for the advice!

The trouble is, there are at least 2 major fuseboxes, plus a couple of "sub" ones. And nothing is labelled as "phone", so it must either have a separate in-line fuse (my hunch) or piggy back on the audio or 12V socket or something.

http://tech.bentleypublishers.com/servle...omp.%20Left.pdf

F55 on here???

Egad Sir, you have found it! I've never seen THAT printed sheet before; I'll go and have a look right now.

Thanks, MRS!

Meh. (Un)fortunately, the fuse is in good health!

Shame, Jim. Are you sure there's no power at the connector or just hoping that was the issue? Is there not BT with the car? I've only ever used the lead to charge with simply because it's tucked in that console. I don't know when BT was standard though

I haven't tested it with the multimeter yet - that's the next thing, but if you plug in the MBU-1000 to a Nokia charger, it lights up, whereas it remains resolutely blank when seated on the cradle.

No standard Bluetooth to my knowledge, although there may be some infuriating sub-menu that I need to turn it on with...

More tinkering ahead, I fear!

Mercs are good for ease of use. My last 2 have had COMAND which makes things like BT trivial.

There isn't a menu to let it know you are using the cradle is there?

There is a "NO PHONE"message on the OBC display on the speedo when you cycle through and the same message is displayed on the head unit when you press the phone buttons. Suggests it's not detecting it for one reason or another...

I just had this reply on the MBClubUK forum:

"Have you checked if the phone control unit is still present and connected to the fibre ring? Power to the cradle comes via the control unit, check that fuse too."

But I don't really understand what it means. What is the phone control unit and why would it be removed?

So, multimeter says "no". No voltage from the "charge" pins on the cradle.

The question is, is it broken, fused, disconnected or switched off...?

Hmm - I know nothing about the phone control unit. I'm at the airport now so not great for googling but, if you're still stuck, I'll have a root around tonight

That's very kind; I'm not sure how much further I'm going to get on my own. I'm hoping to slip in a crafty additional question when the car goes for the brake check...
Please don't disrupt your weekend over it - you've helped plenty already!

No problem, Jim. Did you see this thread?

http://www.mbclub.co.uk/forums/electronics/102372-new-member-w211-phone-no-phone.html

Sounded similar to your issues

That made me smile.

I love this thread!

Glad to keep you amused, as always, bezzer!

MRS - I did see that thread, but for some reason, I passed over it. I don't know where the Nokia Control Unit is in the estate, unless it's among the fuses and the (empty) rack for a SatNav/DVD?

Well, I found it!

If you fold the rear seats forward and remove the sort of hollow storage bin thing, there is an extra panel of carpet that you can unclip and slide out. Under it is some foam insulation and under that are a number of "modules":





And



The first is clearly the Nokia control module, the second is the "hands-free controller" and the last one looks like an antenna controller of some sort and is called a"dual band compensator".

So, it has the right bits. The question is do they work?

Ah - cool. It all looks very "Mercedes". I guess the antenna thing basically gives the phone an external aerial. I suppose you need to check they have juice and the fuse isn't popped for that.

I haven't got a hope of tracking the wiring to find the fuse, but I think there's a clear power cable, so I'll see if it's got anything going to it.
That thread suggested that taking the fuse out for 20 mins and replacing it might help to reset the module, but it sounds like wishful thinking to me!
If the unit is dead, it looks like they are under £50 on eBay.

Is there a lead you can unplug instead, Jim

Yeah, there seems to be a twin orange lead going to a two-pin socket on the unit. It also seems to daisy chain to the other two modules and I suspect it's providing power. The other connector is a great deal more complicated, though of course the two pin could be something else entirely and the power might be a simple pin in the other block...

Hmmm! The thick plottens. It seems that all the interactive bits (phone, TV, audio, SatNav, voice control, etc) are connected on a fibre ring system called MOST. That is now what I think the orange twin cable is.

Yes - that's what I figured that was when you mentioned about daisy-chain. It's great because all the in-car systems work seamlessly together ( in massive contrast to that which I had in my MiTo)

I'm sure they would all work seamlessly - as long as I can get them to work at all. I think I'm reaching the limit of my skills...

I'm just not sure how to determine whether any of the modules are faulty and if so, which. I think a trip to a STAR specialist is inevitable.

And another thing...

I may inadvertently have mentioned that the weather here is rather warm, which it is (just back from a swim in the sea and an hour on the beach. Not bad for November...), but the temperature gauge on the Merc takes quite a time to reach anywhere near 80 degrees and never seems to exceed that.
There seems to be some thought that the thermostats on these cars are prone to failure; should I be worried?

Get it warm and stick the heating on full and go for a drive at midday Jim That should tell you all you need to know. Change it mate if its in any doubt though due to the long drive in January.

Apart from being highly amusing for everyone else and great for my temporary weight-loss programme, is there a serious point to doing the turn up the heating thing?!

No i doubt it Jim. I imagine it would be best to post the question on the Merc forum. Maybe its a known thing about the low/slow temps.

Turning into a bit of a pantomime over the "Service brake!" warning. The seller seems to think he's a bit of a big shot with lots of contacts, but nobody seems to want to run the STAR diagnostics for him as a favour. I've ended up telling him to take it to the Merc. main dealer and I'll go halves with him for the cost of the diagnosis.
I think I know more about the car than he does now, having spoken to Mercedes in the UK and got the full read out from the VIN.
I just want to get it sorted now as I'm not happy driving round with a "Look out, there's a problem with your brakes!" issue hanging over us.
Booked in for 9am tomorrow. Hopefully find out about the MOST ring fault too.