c300h hybrid system failure

[tjcish]

Hi, I'm new to this forum and looking for a bit of help. I took delivery of c300h estate back in August of this year. I love the car, but over the last six weeks or so the vehicle has been running less and less in hybrid mode, i.e. the engine was stopping less and less often when I took my foot of the throttle, to the point where it was only doing this less than half the time that it was when it was new.

Last week, I was driving around, I applied the brakes and the car started juddering. When I moved off from standstill there was a lot more juddering and a delay of two or three seconds before the car moved off. At this point the hybrid system indicated the battery was no longer charging or discharging under braking or acceleration, and I could hear what sounded like a whining noise from the transmission or the hybrid battery system in the boot, and the feel of the brake pedal became much harder? There was no fault message, and it would reset when the car was turned off and on, before failing again a few miles down the road.

Mercedes picked the car up, told me they eventually managed to get it to fault in their garage, rebooted the ECU and told me it was fine. A day later and fifty miles later it failed again. More extremely this time, with initially a transmission failure message, and then a battery failure message. Once parked up it would not start again. It was picked up again, this time the garage said they'd traced the fault to the stop/start button (!!!), so they replaced that, told me it was fine, I drove it away and it failed completely two miles down the road. The mechanics clearly don't have a clue, so I was wondering if anyone on here had any insight?

 

[John Laidlaw]

These engines and gearbox interfaces are quite complex , they need very specialist input from Mercedes HQ when things go wrong- or at least that was my experience when mine packed in at the beginning of this year. In my case it was the gearbox ECU, the symptoms you mention sound very similar to those I experienced.

 

[tjcish]

Thanks, much appreciated. The gearbox ECU has not been mentioned by anyone at Mercedes as yet. I will make sure they consider it, as I have a fear at the moment that I will get a call telling me they have fixed it by tracking the problem down to the interior light or the cupholder!!

 

[rgibo]

Interested in gearbox ECU problem

Hi chaps, was reading the above and it was the only post I could find anywhere online about this.

Was trying to pull away from traffic lights today and pressed the accelerator and got nothing, gearbox just sat there then eventually juddered away to next set of lights where it did the same, juddering when stopping and pulling away. Eventually had to use the manual paddles. Is this similar to the issues you had?

It's done it before but I just dismissed it but upon finding this post I'm thinking gearbox ECU now. Also I get a huge jolt every now and then between 1st and 2nd gear, thinking the two could be related?

Be interested to know what the outcome was of your problems, thanks!

*C300h AMG Plus - Iridium Silver*

 

[lochetive]

Hi folks. My hybrid c300h is also working less on hybrid\battery. To the point where it doesn't kick in at all. I dread having to take it to the dealer in Edinburgh to get it fixed as they are so useless and arrogant.

 

[mercedes13156]

Why not ask Diagnostic World if the ICarsoft 980 or MB2 covers your model. Email them, or phone them. They are absolutely spot on guys.

http://www.diagnostic-world.com/pag...89133-z=563774&p=99689.cfm#content_item_99689

Then you can go to the dealers with a list of things which you know that they need to consider, rather than depending on them footering about in the dark.

I've helped a few Merc owners get a decent result from the Dealers in Edinburgh after being fobbed off, by giving them a written list of fault codes and descriptions of the faults to take with them. You just read the faults and don't delete them so they can see them on their STAR machine.

For £90 against your investment in a C300Hybrid, it's a no brainer.

 

[bembo449]

I think another member may plug into the car for free if they ask pal , I would defo if they are local to me , in my experience being armed with any info before approaching a dealer usually makes no difference at all ! they will still do their own thing

 

[mercedes13156]

I already offer free diagnostics to fellow Forum members and a couple of locals have taken me up on the offer with some success at the dealers.

I'd do the same for tjcish, but Hertfordshire is almost 400 miles away from me and if lochetive is anywhere near Loch Etive, it's about 130 miles and a three and a half hour drive.

The offer is there, though the cost of fuel to get to me and back from Hertfordshire is probably the same as buying the diagnostic kit.

No brainer really!

 

[Craiglxviii]

There are a few members around Herts with diagnostic kit... and we have V6Matty up in Newark who has STAR I think, for whoever in Rutland asked.

130 miles in 3.5hrs?!? Is that driving a Marina?

 

[bembo449]

I have MB2 , autocom and torque pro , the last one is more for live data , im north lincs ( Scunthorpe area ) always happy to help a fellow member

 

[mercedes13156]

There are a few members around Herts with diagnostic kit... and we have V6Matty up in Newark who has STAR I think, for whoever in Rutland asked.

130 miles in 3.5hrs?!? Is that driving a Marina?

No. you've obviously never driven up that way. Check it out on Street View.

 

[Craiglxviii]

No. you've obviously never driven up that way. Check it out on Street View.

We had a family holiday in Scotland once, Dad and I invented the concept of the "Scottish mile" being 40 statute miles as it took us AGGGGGGGES to get from somewhere 40 miles from Stirling, to Stirling.

So going by that math I now understand

 

[mercedes13156]

We had a family holiday in Scotland once, Dad and I invented the concept of the "Scottish mile" being 40 statute miles as it took us AGGGGGGGES to get from somewhere 40 miles from Stirling, to Stirling.

So going by that math I now understand

It's not too bad in the Central Belt where we have decent roads but move more than a few miles from a big town (Stirling, for example) or off the main routes like the A9 or A82 and you're down to 12' wide roads with no markings, no road signs and no fences to keep the sheep off. We got stuck for four miles once behind a very large bull out for a wander down the middle of a road near Inverary on our way to a wedding. We missed the ceremony and dinner. There was no phone signal, no houses, and no other way to get there. It eventually wandered off the road down to the loch for a wee drink and we got on our way. We arrived at the hotel three hours late and explained what had happened only to be told that Hamish (the bull) quite often did that for a bit of fun.

Inverary is only about 40 miles from Glasgow.

 

[Craiglxviii]

It's not too bad in the Central Belt where we have decent roads but move more than a few miles from a big town (Stirling, for example) or off the main routes like the A9 or A82 and you're down to 12' wide roads with no markings, no road signs and no fences to keep the sheep off. We got stuck for four miles once behind a very large bull out for a wander down the middle of a road near Inverary on our way to a wedding. We missed the ceremony and dinner. There was no phone signal, no houses, and no other way to get there. It eventually wandered off the road down to the loch for a wee drink and we got on our way. We arrived at the hotel three hours late and explained what had happened only to be told that Hamish (the bull) quite often did that for a bit of fun.

Inverary is only about 40 miles from Glasgow.

I can picture it. "Old Hamish? Hah!" etc.

 

[umblecumbuz]

Haven't met Hamish, but Rambo inhabits the Abergwesyn passes near me.

Rambo is a ram, and at night he sleeps on the tarmac (one car width with no room for error). You sound the horn, flash your lights, shout into the void and creep forward. Rambo takes exception to this and charges you. If you back off, he gains ground.

The only way to make progress is to act like a ram, and give not an inch, while you try to sell him the dummy and then shoot past!

It's all too annoyingly true!

Umble.

 

[Craiglxviii]

Haven't met Hamish, but Rambo inhabits the Abergwesyn passes near me.

Rambo is a ram, and at night he sleeps on the tarmac (one car width with no room for error). You sound the horn, flash your lights, shout into the void and creep forward. Rambo takes exception to this and charges you. If you back off, he gains ground.

The only way to make progress is to act like a ram, and give not an inch, while you try to sell him the dummy and then shoot past!

It's all too annoyingly true!

Umble.

Rambo sounds like he needs to argue with a Land Cruiser fitted with bull bars...