ECO Stop/start not workin

[SmokeyUK]

I have a 2016 C220 (RHD), and my eco stop/start has never worked since I bought the car in December last year, I have tried various things to try and find out what's wrong, but I am still none the wiser.

• I hooked up my diagnostic tester, and I found no fault codes stored.
• Searched for a secondary battery, which I later found out is only fitted to LHD models.
• Fully charged the battery twice, and retested, the battery is ok.
• Went out for local and long drives with the ac on and off.
• Drove over a long distance in both cold and warm temperatures.

Now I have read somewhere that the right hand drive models have a capacitor instead of a secondary battery, is this right?

 

[Gazwould]

 

[OneForTheRoad]

I have a 2016 C220 (RHD), and my eco stop/start has never worked since I bought the car in December last year, I have tried various things to try and find out what's wrong, but I am still none the wiser.

• I hooked up my diagnostic tester, and I found no fault codes stored.
• Searched for a secondary battery, which I later found out is only fitted to LHD models.
• Fully charged the battery twice, and retested, the battery is ok.
• Went out for local and long drives with the ac on and off.
• Drove over a long distance in both cold and warm temperatures.

Now I have read somewhere that the right hand drive models have a capacitor instead of a secondary battery, is this right?

Under the glove box apparently. Both my c250 and e350 are rhd and have aux battery in the boot.

 

[geoffus]

It would be nice to know why it's not working, then you could turn it back off.
It isn't doing your engine any favours when it's working properly.

 

[Connoisseur]

A couple of threads worth reading about this to help you find the solution are:

Auxiliary battery malfunction | Electronics and Audio

Hi, I've got the above warning showing in my '16 plate C63. When I started the car this morning, the warning was in red, but after driving for a short while it went to white. Oddly, the stop start function is working fine and the car is running perfectly. Does the warning appear if the Aux...

forums.mbclub.co.uk

Auxiliary battery malfunction | Electronics and Audio

Hi, I've got the above warning showing in my '16 plate C63. When I started the car this morning, the warning was in red, but after driving for a short while it went to white. Oddly, the stop start function is working fine and the car is running perfectly. Does the warning appear if the Aux...

forums.mbclub.co.uk

hth

 

[RTR1879]

I've got the same thing, Smokey. Bought my approved-used 2017 C220d in November after coming out of a company car C350e, which was perfect at stop/start as you'd imagine given the hybrid nature of the thing. I expected the same kind of experience. Not so.

It has worked twice, and with no logic as to why at those times. One was last Saturday night when I had to run to the pharmacy at 9.30pm with the car having stood all day. Worked for 2 sets of traffic lights then the @ symbol went yellow again. I might call the dealer and have a chat about it. Should be covered under the warranty.

I've never had a malfunction message though, only always the yellow @. I tend to run around mostly in Eco mode for the coasting mode, especially in motorway runs. Would this have any bearing?

 

[Tonygw]

How did you test your main battery? When mine stopped the battery was "ok" but a little low on voltage. The car started fine and everything worked. But then one day the brake hold functions stopped.
I bit the bullet and replaced the main battery.

And voila it all started working again.. And now I wish it wasn't LOL the stop start is a crap system, so many times its stopped while I am waiting to turn right at a junction looking for the big enough gap etc..

So I have trained the kids to switch it off as soon as the engine is fired up.. seems to be a reliable system so far.. LOL

 

[Muckypaps]

Mine is a 2016, the light very rarely green, eventually the main battery was just managing to start the car.
I replaced both batteries, the green light spends more time on than it is yellow.
It normally goes green in less than 400 meters from first drive of the day, and coolant temperature below 40.
I used my CTEK regularly, but it was the battery replacement that transformed everything.
In my view you can charge the batteries till the cows come home, but if it's not up to scratch it won't work as it should.
My theory to replace both batteries was to make it as near new battery state as I could, ie new cars don't have a problem.
PS, Never turn mine off.

 

[esscee]

Why worry about it, ought to be thankful it does not operate when you least expect it. Picked up my vehicle 3 years ago and as I slowed down approaching a roundabout engine stopped, wondered what problem was. It reluctantly restarted, luckily, and carried on back home. Ever since then as soon as engine started I turn the damn switch off. More grief and trouble than useful as there are so many criteria that have to be valid for it to function correctly.

 

[OneForTheRoad]

Under the glove box apparently.

Why worry about it, ought to be thankful it does not operate when you least expect it. Picked up my vehicle 3 years ago and as I slowed down approaching a roundabout engine stopped, wondered what problem was. It reluctantly restarted, luckily, and carried on back home. Ever since then as soon as engine started I turn the damn switch off. More grief and trouble than useful as there are so many criteria that have to be valid for it to function correctly.

Ask Gazwould about pulling the fuse , he invented it ,don't you know ..

I never did post them lollies.

 

[markjay]

You can buy a basic battery tester e.g. Ancel BTC200, or check the battery using iCarsoft or Carly, it will show you a figure called State of Health (CoH).

The figure is calculated as the percentage of the measured CCA compared to the battery's nominal CCA. So the SoH for a battery measuring 400CCA and rated 800CCA is 50%. I am not sure when the SoH is 'too low', but from reading online it seems that 40% or above is acceptable (batteries degrade over time).

The other relevant figure is State of Charge (SoC), which is simply a percentage compared to a fully charged battery, based on measured battery voltage. So the SoC of a battery measuring 12.7v will be 100%.

This however applies only to Lead-Acid batteries, so you can't use it to test a capacitor, though (unlike Lead-Acid) a failed capacitor should flag-up an error on the dash or scanner (or both).

 

[wongl]

Why worry about it, ought to be thankful it does not operate when you least expect it. Picked up my vehicle 3 years ago and as I slowed down approaching a roundabout engine stopped, wondered what problem was. It reluctantly restarted, luckily, and carried on back home.

If one use the Start/Stop for a week or so, one will soon learn how adapt one's driving style to anticipate and manage the start/stop feature. With practice, and once mastered, one can even hold the car stationary by pressing gently on the brake pedal without triggering the start/stop cycle.

 

[wongl]

I used my CTEK regularly, but it was the battery replacement that transformed everything.
In my view you can charge the batteries till the cows come home, but if it's not up to scratch it won't work as it should.
My theory to replace both batteries was to make it as near new battery state as I could, ie new cars don't have a problem.

Keep using your CTEK charger on your new battery to extend its useful serviceable life.