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

[Jaunty]

johnboy99 Glad to read it was sorted. Mine continues to be fine. Debden sorted it more by luck than judgement for me though I think as they do not seem aware of it as a known issue unlike other dealers...

 

[systemler]

Hi guys. First post. Just last night picked up a 1 year old C300h AMG Line Estate Premium Plus in Polar White with 19" 788 AMG wheels on non run flats . Will stick some pics up when I figure out how. Coming from a Z4 so a bit of a change - but a big saving on BIK tax and a lovely a motor. And 3 and a half years of junk in the loft can now get taken down the tip haha.

First Question - On the 3 hour drive home (A roads, M25 then London suburbs) from the independent dealer, even with the battery up in the 70% area and in Eco Mode the car would not start/stop or use electric. I even turned the air con off to give it a hand. Music, Sat Nav and lights were all on but even so I thought in that situation it should cut in at the traffic lights. This morning I didn't drive the car but I did get in and start it. The battery was at 75% I think and the diesel came straight on. I thought it would start in Electric mode if I was stationary? Maybe a bit too soon to worry - but should I?! I can try and get it booked in to MB this weekend if i need to.

(PS For those W205 owners without the hybrid, you can't actually turn of ECO start/stop on these, so it is not that.)

Thanks for any thoughts.

hi i am new to the forum and joined because i bought a c300h w205, after having the car for 2 weeks i felt stop/start and hybrid was not working how it should, i decided to put the car in my local dealer at cheshire oaks mercedes and i am so glad i did, the car was NOT showing any faults on the drivers display but stop/start never really worked, after mercedes had the car for a few hours they rang me to say car was fixed and ready to collect, the fault was MAIN battery failed ? although now issues showing, the car is just under 3 years old the battery was replaced free under warranty by chesire oaks merc so full credit to them, the car is now a dream its like brand new, just did a drive i normal do every day and i would say 40% of it was on hybrid, hope this helps others as i did not think it was the main battery, i am also having the heated seat bases in both front seats repaired under warranty as both have failed, only the back part of the seat heats up, just waiting on merc to send parts from germany, top marks to mercedes cheshire oaks though, no problems with warranty claim and very helpful

 

[grober]

I think the small hybrid battery in the C300h is located under rear seat [or boot floor] from this picture

here is the latest diesel powerplant in this video the " box" is the electric drive controller I believe??

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[systemler]

very interesting grober thanks for that, i had a c220 w204 but had had this hybrid for 3 weeks now...the power difference is amazing no lag at all, in sports + mode it feels like it wants to rip the rear tyres off there rim.

 

[systemler]

just an update incase it helps anyone else in the future, just had both heated seat pads replaced under warranty by cheshire oaks merc who have been brilliant, car was in for a day and half, had a 2017 plate c250 while mine was in for repair, really nice fast car but not as refined or as quick as my 2015 plate c300 hybrid, looking at the clocks in the c250 it was doing around 38mpg my c300h was at 44mpg...not much really but it all adds up

 

[zipdip]

Well my merc is now 11 years old now ,last year I thought about the C300 but with so many problems I decided against it,I suppose if it is a company car and under warranty then ok but as a second hand car buyer the costs could be crazy,it is interesting that many of the problems are traced back to the main battery in the boot or under the rear seats,my W221 has a starter battery and then a much bigger one behind the rear seat it is this one that does everything else in the car and needs to be in good shape or you get problems,it seems that the C300 also require this battery to start the car in certain circumstances,it all seems a bridge too far for that battery,which you can bet will cost at least £300 if you have to replace it,I think my original decision not to buy the C300 was the correct one.

 

[OliOwl]

Hi folks. Sorry to drag this back up, but can someone describe this “gear jolt” that was being mentioned please?

I recently picked up a 66 plate C300h and I can’t decide if it is suffering the same problem.

 

[MattDomine1981]

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

I’ve had the exact same problem. No stop start and never running in electric only. Battery charges on coasting and braking and getting boost from electric motor when accelerating. Had the 12v battery replaced today so will hopefully find out tomorrow if it is fixed when I go for a drive. Interestingly the battery i removed has a best before date of Feb 2018 so probably due to be replaced.

 

[Zenfold]

Quite late to the party. However I recently bought a 2015 c300h and the hybrid system is really intermittent. In a weeks driving it has only been on electric mode only for around 10 minutes. No warranty left so I'm not silly to go to the dealer and spend thousands on it.

Has anyone found a potential fix for this? Battery charges fine, around 70-90% usually never below 60 unless in sports mode with my foot down all the time.

Do I need to change the 12v battery? Telematics upgrade? Software upgrade? I've read everything previous members have written, just wondering what fixed it long term.

Cheers

 

[Zenfold]

I've so far cleaned the injectors, filled the adblue, full serviced the engine and gearbox. Still intermittent. Will change the battery next week and see how it goes.

 

[Jordanmaguire]

What models was this affecting guys? Mines the 2015 and its currently working but intermittently, thinking of just replacing the battery.

 

[Jordanmaguire]

I’ve had the exact same problem. No stop start and never running in electric only. Battery charges on coasting and braking and getting boost from electric motor when accelerating. Had the 12v battery replaced today so will hopefully find out tomorrow if it is fixed when I go for a drive. Interestingly the battery i removed has a best before date of Feb 2018 so probably due to be replaced.

What year model is was this please

 

[Jordanmaguire]

I've so far cleaned the injectors, filled the adblue, full serviced the engine and gearbox. Still intermittent. Will change the battery next week and see how it goes.

Did it work after swapping the battery?

 

[Jordanmaguire]

12v battery - the hybrid now works again!!!!! My stop start was not working at all, they guys in Mercedes Belfast replaced the 12v battery (wasnt showing a fault) and hey presto - it's a hybrid again! Awesome, it drives in electric very soon on a run at low speeds, it stop starts at traffic lights. Fuel consumption up about 10mpg!! This is the fault if anyone is having a similar issue. Even the dealer was surprised to learn this! All door handle lights replaced. Feels like a new car again. Good work Mercedes Belfast.

Did the hybrid just start working again after the swap then? Also what are you getting mpg wise roughly?

 

[Jordanmaguire]

I wonder if it is due to some recent update. I bought my C300h in April 2015 and last winter both the start and stop and the hybrid function were working fine. However, since the start of the cold season this year I started experiencing the same issue as you, even after long journeys: the battery charges up to 89%, but the diesel engine is always running, even when the car is stationary and in Economy mode.

I had a similar issue with the start & stop function on my previous car (2010 Audi A4) and the root cause then was a faulty aircon sensor.

Tomorrow my C300h will be checked by the dealer and I'll definitely let you know the outcome.

Fingers crossed ...

I've taken mine in today and they are saying it's my started battery and a faulty air con sensor, did yours work after your changed?