Question for 2011 C Class owners - Stop Start

[ace571]

What's the outside temperature like though?

I believe it doesn't kick in if it's very cold outside

So from the manual



I am not sure what that last sentence means in reality!

Hi Mark, I read this part of the manual and the temperature is not the variable affecting my car's SS. I drove to work this morning in the snow, outside temp 1.5 C, yet SS was green and working. Yet on drive home it was amber for the whole journey, temp 5 C and a 1 hour m/way drive covering 54 miles.

30 mins later took my kids swimming, moved from amber to green within 1 min of restart.

There is no consistency to its behaviour. Master Tech @ MB dealer agrees it's not right.

Hopefully a simple fix.

It's definitely not working correctly

 

[Kingy68]

After reading this thread I kept an eye on the eco button on mine (61 plate C220). Other than start up (getting car to temp etc) its been solid green and the start stop (which I've grown to like a lot) has been working perfectly. Thats in temps ranging from -3 and over this weekend it's been short journeys (10 mile to 80 mile round trips).
It does sound like yours is not working as it should do.

 

[ace571]

Car went into MB Beaconsfield today. The guys spent quite a while trying to work out what could be causing this, but couldn't pin point anything. It's been logged with MB Technical as nothing obvious is causing it. Sounds like it's a watching brief...

It's not gone green at all in since I last posted on here - constantly amber. However the MB guys have today reset all the systems and for now it looks to be working normally. Hopefully it will stay that way.

 

[Red C220]

The only time I switch the system off is in heavy stop-start traffic which edges along. Otherwise it's on all the time.

After 4 months I've got quite used to it.

 

[ace571]

An update on this stop-start problem.

After the visit to MB Beaconsfield in Dec the car appeared to be running normally, but then the problem resurfaced with prolonged periods of driving with the ECO light amber (indicating it's not operational). One particular stretch of 3 days and 350 miles of m/way commutes - constantly amber.

MB Beaconsfield promised to flag it with MB Technical and then let me know. I received no follow up - disappointing TBH.

On the recommendations of several on this forum I booked the car into MB Basingstoke (Tony Purslow).

Wow, terrific service. After explaining the fault the car was booked in, as it happened within a week with a loan car

Service chap (Jim) rang me a day before the booking to say that they had done some in depth reading up on this fault with Technical/MB factory - they suspected the fault to be the battery temp sensor playing up - apparently a handful of cars have been reported to be having the same fault. This sensor has been identified as the most likely cause. Jim had ordered the part in on this basis.

The sensor has been replaced and all seems to working as it should. Worth noting that no fault code is thrown up by this.

From my experience of the fault, the SS not working was more so when the weather was particularly cold, or the car was used for short journeys only, so could explain the temperature problem.

Thought I'd share the outcomes in case another owner experiences the same. Also thought I'd share how great MB Basingstoke were - in a different league to MB Beaconsfield certainly. Highly recommended

 

[ace571]

Well it looks like I spoke too soon

The SS worked perfectly for 5 days. I didn't drive the car at all on Sunday, got in it Monday morning, drove 50 odd miles on the motorway - light remained amber. Drove home 5 hours later, worked normally.
Then yesterday, amber all day, despite covering 110 miles.

Called the dealer - seems this one has got them stumped. No fault codes either... They are checking with MB UK/Germany.

Maybe it's linked to the cold snap? Are other facelift W204 owners able to use SS in this current cold snap? Does the light turn green quickly, as it does when the weather is mild?

 

[Kingy68]

Sorry to hear the problem is back.

Are other facelift W204 owners able to use SS in this current cold snap? Does the light turn green quickly, as it does when the weather is mild?

We've had light snow/ice and minus temps over the last week and the SS in our C220 has worked normally once the car/climate etc. is upto temp. It's yet to play up at all and does get left parked up for days at a time before doing a 200 mile journey.

 

[ace571]

Thanks Kingy, appreciate the feedback. At least it tells me what it should be doing.

 

[Red C220]

No problem with ours despite freezing temperatures and snow on the ground.

Drove to Putney and back yesterday from Godstone, it was lit green within three miles of a very cold start.

 

[ace571]

Cheers Red.

It's been booked back in to Tony Purslow for investigation. Can't fault their service - going in tomorrow and getting me back into their E350 loaner.

 

[ace571]

Update number 2

Tony Purslow checked over the car over 4 days, including a full data download to MB HQ, both static and driving. No faults found. No fault codes logged either.

All control units have been reflashed with the latest software.

The battery temp sensors are however considered the main culprit here and there appears to be a faulty batch of them. The sensor that was replaced first time round was replaced again, and guess what, all is working perfectly!

Hopefully this post isn't the kiss of death on this one!!

 

[Frugal]

Thanks for the very helpful update. My amber/green system has behaved exactly as it should until a couple of weeks ago when the same thing occurred - after a long motorway trip (albeit at around freezing) the green light went to amber. Since then it has been fine except for a repeat of the problem after another motorway trip of about 150 miles last weekend. First service not due for another 10,000m so I'll keep a watch and hope it doesn't become a big enough pain to need a trip to MB.

 

[ace571]

Thanks for the very helpful update. My amber/green system has behaved exactly as it should until a couple of weeks ago when the same thing occurred - after a long motorway trip (albeit at around freezing) the green light went to amber. Since then it has been fine except for a repeat of the problem after another motorway trip of about 150 miles last weekend. First service not due for another 10,000m so I'll keep a watch and hope it doesn't become a big enough pain to need a trip to MB.

Hi Frugal, exactly how the problem started on mine. From my original post in this thread:

However on a number of occasions I've noticed it has become amber, sometimes after 45 mins/1 hr of driving.

The SS system is a pretty complex setup taking readings from various sensors and parameters, however turning amber after a long run is not a circumstance you would expect to see (the car will be at operating temp, the cabin will be warm, the battery charged etc etc)

It could well be the same issue as mine had. Hope it fixes itself, or if it doesn't this thread helps you. From my experience Mercedes are clearly still learning with the SS system as it's so new and only on the latest cars.

 

[Red C220]

Well, it seems I've been blighted with the same issue.

My Stop Start system has worked perfectly for 8,500 miles. Yesterday, after not a particularly long trip in town it went to amber and hasn't retunred to green once in two days of driving.

Booked in next Wednesday (11/04/12) along with a request to check headlamp alightment again as I'm still being flashed frequently.

Will update when I know more.

 

[Frugal]

Well, it seems I've been blighted with the same issue.

My Stop Start system has worked perfectly for 8,500 miles. Yesterday, after not a particularly long trip in town it went to amber and hasn't retunred to green once in two days of driving.

Booked in next Wednesday (11/04/12) along with a request to check headlamp alightment again as I'm still being flashed frequently.

Will update when I know more.

It certainly sounds like a warranty issue. Thankfully mine has behaved itself since my last post (#32) so I'm keeping fingers crossed that this contnues. I'll be interested to learn in your next post how you get on.

 

[ace571]

Well, it seems I've been blighted with the same issue.

My Stop Start system has worked perfectly for 8,500 miles. Yesterday, after not a particularly long trip in town it went to amber and hasn't retunred to green once in two days of driving.

Booked in next Wednesday (11/04/12) along with a request to check headlamp alightment again as I'm still being flashed frequently.

Will update when I know more.

Sorry to hear this Red. Hope it's the same sensor fault as mine, therefore easy to rectify. Good luck.

 

[Red C220]

Sorry to hear this Red. Hope it's the same sensor fault as mine, therefore easy to rectify. Good luck.

Well as a result of your experiences I can drop the car off and explain there is a known issue with the Battery Temp Sensor.

Fortunately, this is one of those things that actually doesn't matter. You can continue driving and there's no problem, it's just a nuisance.

Ironically it started working again today, so it spent a little over 30 hours inoperative. This seems to mirror the other cars reported in this thread, so at least we have some consistency. It'll still go in though, may as well get it addressed.

 

[mjrennie]

I get the amber thing too, it's clearly related to factors already mentioned and therefore pretty intelligent. Just knock the button off if you don't want it. I'm indifferent to it, at the moment.

 

[Frugal]

Well as a result of your experiences I can drop the car off and explain there is a known issue with the Battery Temp Sensor.

Fortunately, this is one of those things that actually doesn't matter. You can continue driving and there's no problem, it's just a nuisance.

Ironically it started working again today, so it spent a little over 30 hours inoperative. This seems to mirror the other cars reported in this thread, so at least we have some consistency. It'll still go in though, may as well get it addressed.

Mine seems to be working fine now but I'm keeping an eye on it and would be grateful to learn how your dealer responds here.

 

[Red C220]

Car went into Dealer today (Lookers Redhill). I find them very helpful, happy to collect and drop off, or run me home or provide a car if I need one.

Technician says problem is exactly as described on this thread, I need a new battery temp sensor as I have one of the duff ones. It will be ordered in and the car will go back for a morning to have it fitted.

I also had the lights adjusted again, they were still a little high, so hopefully I'll not be blinding people at night now.

All together all rather easy.

I had a sit in a new B class whilst in there, Like the driving position but I'm worried the boot will be a bit small after a C Class Estate.