New C300h Hybrid Owner - no start/stop or electric even on Eco?

[steve333]

But it is the normal battery that is causing the problems it seems

Is the technician saying the standard car battery is stopping the car from switching to electric in Eco or comfort mode when at normal running temperature and the hybrid battery having enough charge to cut in?

 

[fab1975]

Is the technician saying the standard car battery is stopping the car from switching to electric in Eco or comfort mode when at normal running temperature and the hybrid battery having enough charge to cut in?

He did not go into the exact details, but I can share my practical experience of the fault before it got fixed:

- the battery charger indicator always stayed within a much higher range than usual (between 73 and 89%).
- the diesel engine was always running, even in the situations where it would have normally been turned off automatically (i.e. while stationary, or braking, or driving downhill).
- the electric engine did not get activated under any circumstances, including the "power boost" that you would normally get when accelerating hard (i.e. kick-down).
- the above behaviours were the same in any mode (Eco, Comfort, etc) and with different outside temperatures.

In practice, it was like the C300h turned into a C250d (still a nice car), but I am glad I got it fixed.

Credit where it is due...well done to MB Chester

 

[Organum]

He did not go into the exact details, but I can share my practical experience of the fault before it got fixed:

- the battery charger indicator always stayed within a much higher range than usual (between 73 and 89%).
- the diesel engine was always running, even in the situations where it would have normally been turned off automatically (i.e. while stationary, or braking, or driving downhill).
- the electric engine did not get activated under any circumstances, including the "power boost" that you would normally get when accelerating hard (i.e. kick-down).
- the above behaviours were the same in any mode (Eco, Comfort, etc) and with different outside temperatures.

In practice, it was like the C300h turned into a C250d (still a nice car), but I am glad I got it fixed.

Credit where it is due...well done to MB Chester

Very interesting as my E300h had the same problem and the same fix at mk mercedes last week. I have asked for an explanation as to how the 12v battery could fix the intermittent hybrid mode since I never had any problems with starting or battery life. In addition the hybrid still, now very occasionally, cuts out during running and yesterday after a 2 hours run happened again even with the new battery.
I am about to send the dealer a photo of that condition with a request for information as to what conditions could trigger that.

 

[fab1975]

Very interesting as my E300h had the same problem and the same fix at mk mercedes last week. I have asked for an explanation as to how the 12v battery could fix the intermittent hybrid mode since I never had any problems with starting or battery life. In addition the hybrid still, now very occasionally, cuts out during running and yesterday after a 2 hours run happened again even with the new battery.
I am about to send the dealer a photo of that condition with a request for information as to what conditions could trigger that.

You made a very valid point, even if when I got my car back I did not think about it and just accepted the explanation. To be fair the technician did not say that the standard battery was flat or completely out of order, but only that it was faulty.
I have been driving my car for over 3 days now and so far so good.
Please let us know how you get on with your E300h, as well as the outcome of your enquiry.
Cheers

 

[Organum]

You made a very valid point, even if when I got my car back I did not think about it and just accepted the explanation. To be fair the technician did not say that the standard battery was flat or completely out of order, but only that it was faulty.
I have been driving my car for over 3 days now and so far so good.
Please let us know how you get on with your E300h, as well as the outcome of your enquiry.
Cheers

I had no reply from MK Mercedes as to the explanation requested. Today I had a re-occurrence of stationery car with engine running, only for a few minutes but still not what I expect since this was the start of the rot before.
I love this car for its pure comfort and quietness, as well as amazing economy for a car of this size, hence my disappointment and dread of talking to the dealer. Each time its 'oh there is nothing on the logs but we have done a software update and see how you go'.
Thanks for sharing this information which is a great help.

 

[Jaunty]

Also very grateful for the all detailed info on the hybrid side. Thread could be a useful resource for other owners.

Also enjoying the car but it is just a diesel at the moment as the hybrid side is non existent. Gathering as much info in advance of the earliest service I could get of 20th January. So far

1. Fix hybrid
2. Gearbox ECU for 1st/2nd gear jolt
above are main issues other ones are
3. See if can get acoustic glass for front as at motorway speed does sound like the window is open a smidgin
3. See if reversing mirror can go back to normal more quickly
4. Get MB Me set up - dealer needs to see V5.

Have a great weekend all. Tried to attach a pic to lighten the thread.

 

[Organum]

Had a call back from the dealer's senior tech guy who seemed a reasonable guy.
The line was that hybrids are a complex car and many parameters are tested before hybrid is allowed as a functioning system. I asked how the system could test for a faulty battery whilst the car was running as I still get the hybrid turning off during driving with a fully warm engine and reasonable outside air temperature.
Did not know other than repeat the 'complex car' mantra.

I agreed the car was so much better and mainly retains hybrid mode with occasional hybrid off with hot engine and would monitor the situation.

Something in me says Mercedes don't have confidence in a system which offers zero road tax, better economy and much reduced emissions.

 

[Organum]

'explanation' from Mercedes

FWIW here is what Mercedes reported today. Not a good explanation for me since the car started perfectly and 12v battery kept charge just fine but hybrid did not engage or engaged intermittently. How did the system know the battery was faulty under running conditions? That said since the 12v battery was changed hybrid returns to normal operation.

The note from Mercedes:

“The reported symptoms are possible with a defective or weak 12V battery.

When the engine is in E-Mode the electric machine is powering the driven axle.
The engine and electric machine are de-coupled via the wet clutch.

As the electric machine is being used to power the driven axle it cannot be used to start the engine due to the speed difference.
Therefore the engine is started using the 12V battery and starter motor.

If the 12V battery condition does not meet the requirements the hybrid system will not operate.

As a simplified analogy consider the affect the weak 12V battery has on the Eco stop/start system.”

 

[Jaunty]

FWIW here is what Mercedes reported today. Not a good explanation for me since the car started perfectly and 12v battery kept charge just fine but hybrid did not engage or engaged intermittently. How did the system know the battery was faulty under running conditions? That said since the 12v battery was changed hybrid returns to normal operation.

The note from Mercedes:

“The reported symptoms are possible with a defective or weak 12V battery.

When the engine is in E-Mode the electric machine is powering the driven axle.
The engine and electric machine are de-coupled via the wet clutch.

As the electric machine is being used to power the driven axle it cannot be used to start the engine due to the speed difference.
Therefore the engine is started using the 12V battery and starter motor.

If the 12V battery condition does not meet the requirements the hybrid system will not operate.

As a simplified analogy consider the affect the weak 12V battery has on the Eco stop/start system.”

Yeah makes no sense really. At least it is an easy fix though. Hopefully I will get to experience what driving a hybrid should feel like after service (now due 26th Jan - not easy to get booked in in London).

 

[Jaunty]

MB Loughton had my car all Thursday and Friday but weren't able to diagnose what the fault with the hybrid was. I told them specifically when booking the car in that changing the aux battery was known to fix it but they haven't even tried that yet. No battery fault showing and "can't just try a new battery out as if not diagnosed they may not be reimbursed by MB under the warranty if that isn't the problem".

They have no loaners and I need the car this weekend, so picked up this afternoon and have to take back next week...

 

[Organum]

Oh dear. Can't they even recognise the hybrid not working?

Trouble is that my local service manager had no idea. They know the eco stop/start system but know nothing about hybrid which should be their star sales feature.

 

[steve333]

Although I've not had any hybrid related issues as yet (had the software update on the autobox which is a known problem) I do like the car a lot but out of warranty run the risk of large bills if anything goes wrong with the hybrid system(judging by the posts in this thread main dealers in the uk know little about these cars,I know they're relatively new to mercedes but doesn't give much confidence if problems occur).My car is just a year old with 12,000 miles on it and with all the bad diesel related press(banned in London in the future etc) will go back to a less complex petrol before my car is out of warranty,wondering if I should have looked at a c200 petrol now but the zero tax and impressive mpg swung it ....

 

[wivenhoe]

Although I've not had any hybrid related issues as yet (had the software update on the autobox which is a known problem) I do like the car a lot but out of warranty run the risk of large bills if anything goes wrong with the hybrid system(judging by the posts in this thread main dealers in the uk know little about these cars,I know they're relatively new to mercedes but doesn't give much confidence if problems occur).My car is just a year old with 12,000 miles on it and with all the bad diesel related press(banned in London in the future etc) will go back to a less complex petrol before my car is out of warranty,wondering if I should have looked at a c200 petrol now but the zero tax and impressive mpg swung it ....

Stay with the complex and get a C350e !

 

[Jaunty]

Oh dear. Can't they even recognise the hybrid not working?

Trouble is that my local service manager had no idea. They know the eco stop/start system but know nothing about hybrid which should be their star sales feature.

They agree it is not working but say they don't know why even though I've told them of a known fix. You'd think an MB dealership tech would know of any issues to troubleshoot but it seems not...

 

[Jaunty]

Oh dear. Can't they even recognise the hybrid not working?

Trouble is that my local service manager had no idea. They know the eco stop/start system but know nothing about hybrid which should be their star sales feature.

May I ask you what dealership sorted you out? So I can refer mine to give them a call!

 

[Organum]

Milton Keynes. They said the battery showed up faulty on test and changed under warranty.

Even though in truth they could not explain why it fixed the hybrid it has certainly done the trick on my car at least.

Good luck with getting its fixed.

I am wondering if this hybrid business is to do with the Renault joint venture thing.

 

[ScotCLS]

I've had cars which do all sorts of strange things when the main battery is faulty, although the car would start fine, I've had wipers and washers come on randomly, indicators working outside but not showing internally, internal lighting not working properly etc.

In any car that is showing some electrical "madness" first thing I would do is change the battery.

 

[Organum]

Thinking about this logically the one common factor in all fixes has been disconnecting the battery in the act of changing it.

This will have the effect of a hard reset on the computer which clearly looses all power.

in my days designing electronics a standard problem was initialising memory which became corrupted due to bugs with random errors and often unpredictable results. If the initialisation routine after soft reset was incorrect this memory would often not be restored to initial values.

If the battery was not disconnected during the often software updates a hard reset would not take place.

In my mind this will explain exactly why the hybrid became more and more erratic.

it would be useful to know if anyone has the intermittant hybrid problem and check with disconnecting the battery, wait for one minute (est.) and then reconnect.

All this assumes the computer will return to default conditions without dealer intervention!

Oh the joys of modern computerised cars.

 

[Jaunty]

MB Loughton had my car all Thursday and Friday but weren't able to diagnose what the fault with the hybrid was. I told them specifically when booking the car in that changing the aux battery was known to fix it but they haven't even tried that yet. No battery fault showing and "can't just try a new battery out as if not diagnosed they may not be reimbursed by MB under the warranty if that isn't the problem".

They have no loaners and I need the car this weekend, so picked up this afternoon and have to take back next week...

So dropped car back Monday 8.30am. No loaners and a bit of a trek to get in to the city from Loughton, but hey ho. No news so called 4pm today hoping to get some positive news and collect tonight. Chased twice. Get a call at 6.15pm. "Sorry not looked at it yet. No bays free and/or limited techs with any hybrid knowledge". Promised it will be looked at tomorrow...I've said if they need it longer I need a loaner. Not updated the gearbox eco or map software over 4 days either. Not the best experience to start off with MB service!

 

[steve333]

So dropped car back Monday 8.30am. No loaners and a bit of a trek to get in to the city from Loughton, but hey ho. No news so called 4pm today hoping to get some positive news and collect tonight. Chased twice. Get a call at 6.15pm. "Sorry not looked at it yet. No bays free and/or limited techs with any hybrid knowledge". Promised it will be looked at tomorrow...I've said if they need it longer I need a loaner. Not updated the gearbox eco or map software over 4 days either. Not the best experience to start off with MB service!

The gearbox update/map software could be done by any mb technician and the least they could do considering your car is sat doing nothing is find a loan car for you,good luck with some progress today......