rom1

Had in active stop start for few months, would get the A on the dash display but only stayed yellow never turned green, switch on console would be green, tried regulator under passenger foot well did not work, changed main battery under bonnet and stop start worked straight away, never had any error messages or warning lights.

Just hope it can help someone in same position as me.

blizzard12

Thanks for sharing!

rom1

This is how it should look for it to activate.

ernieh

Bit late in the day as you've changed the battery, but you might have found that charging the battery fully would have given you the same result. It will be interesting to see how long the system works for as, it seems to me, that although there are a number of parameters that affect the operation of the s/s system, the main one is the state of charge of the battery.

Ernie

rom1

Battery was replaced under used car warranty from idependant dealer, battery comes with 3 yr warranty and is designed for stop start vehicles. doubt I'll be keeping it that long.

sr5959

Abohunu

My Start/stop stopped working since some months ago, my dealer told today me I need to replace the main battery because is not retaining the voltage or something like it, Car is 2.5 years old. Should this be covered by warranty?

rustybear3

Absolutely! 100%.

CJG

On this topic, I’m curious to know who uses this? I turn it off when I start the car. Seems like it just puts extra wear on the starter, timing chain, etc.

xxnonamexx

where is the battery located in the 2018. Mine is one month owned and I noticed it works when it wants.

Gazwould

Like most Eco stuff , stop / strain , egr , dpf , all bad for the engine .

sr5959

Yes it should be. I had exact same issue they replaced the battery for free. I’m a fan of the start/stop.

rustybear3

Really? Show me a quote or reliable source that says so?

chrisdean

If you think that the system is failing just turn off the a/c and see if that encourages the green light to come on. Quite often happens with mine.

offagain

I had a Porsche with the stop-start system and it seems to rarely come on / operate as normal. Porsche being Porsche documented a lot of this:

http://www.porscheownersmanuals.com/...-Stop-function

Its not the Mercedes system, but it does cover the aspects where it wont work. I am sure there are more for the W205, but its interesting to understand the potential situations when stop-start is inactive.

xxnonamexx

I have a 2018 C 300 and noticed the start stop green light button is activated on console. Also on dash its green when I am at a traffic light but I noticed sometimes at a traffic light it doesn't "activate".