W204 forgot the time

[richardstubbs]

Bit of an odd one: Just been away for a week, and left the car in the airport car park in Manchester. Got back, everything fine, but the time on the dash was wrong. Like, completely wrong by a few hours and some minutes. I had to stop and set it because it irritated me, and now it seems fine. The car is a 2012 W204 C220CDI which I've had for a year or so without issue, except: It has stop start which used to work but now the auxiliary battery fails to charge (on or off the car - it's 11 years old and broken and I'm too tight to replace it) and "ECO" stays permanently yellow. Could this be related? Does it use the auxiliary to keep the clock powered perhaps? It's been left for a couple of weeks before now with no problem.

Has anyone else experienced this? I know it's not the biggest problem ever...

Thanks,
Richard.

 

[Gazwould]

Leave the Stop Start not working .

You can completely remove the auxiliary battery saving 5kg and it's only function is SS.

 

[Srdl]

It could just be that the main battery voltage was a bit low. Low voltage can do all sorts of funny things to a Mercedes systems. Perhaps just give it a good run and see whether it happens again.

 

[richardstubbs]

Thanks for the replies; I guess nobody else has experienced the same thing then? It hasn't done it again and I can't fix a fault which isn't present so that's that for now. Hopefully it won't come back.

The battery is only a year old and it had been driven two and a half hours to Manchester first, so probably not that although who knows? Could just be marginal voltage after a week standing and a (very) cold start.

I'm aware that I can remove the auxiliary battery but I can't really see that saving 5kg has much purpose on a vehicle which weighed over 1700kg on the MoT brake tester, so I reckon I'll leave it and avoid the live cables rattling about in the boot. I might even replace it one day because (horror to some) I quite like the stop/start. It would have been handy the other day when I was stopped for ages on the M6 so I switched it off, only to have to fumble about to start it again when the traffic suddenly started moving. I felt like a bit of an idiot to be honest.

 

[Gazwould]

Up to you , the majority would delightfully not have it working because your main battery , starter motor , alternator , drive chain tensioner and engine mounts will thank you for it .
Whilst saving a mere 5kg by removing it I also sold it for £30 which would take many years to show up as a Stop Strain fuel saving.

If you think it's a properly engineered robust system with supporting components think again , a bit like the crazy front 295mm and 300mm rear brakes on a +1700kg car .

 

[richardstubbs]

Up to you , the majority would delightfully not have it working because your main battery , starter motor , alternator , drive chain tensioner and engine mounts will thank you for it .
Whilst saving a mere 5kg by removing it I also sold it for £30 which would take many years to show up as a Stop Strain fuel saving.

If you think it's a properly engineered robust system with supporting components think again , a bit like the crazy front 295mm and 300mm rear brakes on a +1700kg car .

I'm not quite clear what your agenda is here - I posted about the clock, and asked whether anyone else had experienced the issue (clearly not) and if the defective auxiliary battery has any bearing on it. You haven't answered that question but seem to want an argument about something else.

In fact I quite like the car as it was designed and built, which is why I bought it (buying a car I don't like would be odd, no?). I paid a little more for a post-2011 car because of the better fuel consumption, delivered in part by the stop-start, and in general I'm very happy with it. It performs as well as if not slightly better than the W203 C270CDI I had before and is averaging around 15mpg more. The only downside is that it sounds like a tractor in comparison, but I can live with that.

The components you mention are designed and sized for the stop start system, it's not like it's just a software change. For example the starter is rated at 2.5kW as opposed to 1.7kW for the non stop-start model. Also, my brakes are excellent - not sure what you mean there, plus they're a pretty tight fit in the standard 16" wheels.

The best Mercedes I ever had though was a W124 250D saloon. Hopefully that isn't contentious