ECO mode always yellow

[Dannyboy75]

I've noticed my ECO indicator below the speedo is hardly ever green these days, so stop/start is hardly ever available. Occasionally after a long run it might turn green, but then goes yellow again after a couple of stop/starts.

I assume this is battery related, so have been trying to read up. From what I can gather, it's the auxiliary battery I need to replace? I'm not sure which battery this is though, as have seen conflicting advice (but most seem to say the aux battery is the one in the engine bay). However, the battery in my car's engine bay looks bigger than the one in the boot. I would've expected the aux battery to be the smaller one of the two?!

Car is a 2014 C-Class Estate "AMG" Sport 220 CDI (W204).

Thanks
Danny

 

[BlackC55]

It could be either battery.

Plugging it into a Star will help to diagnose it.

Buy genuine batteries. There is a difference.

Id be quite happy if the stop start stopped working. It just annoys most people imo.

 

[Fastcar155]

Hi , Should starter and auxiliary batteries really be both changed at the same time ?

 

[BlackC55]

It depends if they are both faulty or not. Some cars we have to, some we don't.

 

[Dannyboy75]

It could be either battery.

Plugging it into a Star will help to diagnose it.

Buy genuine batteries. There is a difference.

Id be quite happy if the stop start stopped working. It just annoys most people imo.

Thanks, will check both batteries. Any idea which one is the auxiliary though?

Tbh it doesn't bother me if I have stop/start or not, but I'm thinking of selling it in the next few months and would like to be able to say that there are no issues with it (especially if I sell it privately)

 

[BlackC55]

The smallest one.

 

[NewbieAMG]

mine's been mostly yellow past two weeks or so and rarely goes green. that's on a c63s. I've initially attributed it to the colder temps but might be wrong

 

[Teego]

Not necessarily a battery problem. Certain preconditions must be met before symbol goes from yellow to green. Check the manual.

 

[Dannyboy75]

Good point. Current list here - not sure if all these would apply to my 10-year old C-Class, but I guess most will.

Mercedes-Benz

 

[Teego]

That's about right.