Mercedes Diesel software update.

[Botus]

Thank you Blobcat, I did do a seach looking for threads, as I know how annoying repeating stuff is.

Not been able to find it thus far, will perceiver, but still welcome comments.

BTW: When you say further up, you mean I only get 9th by breaking the law...

Germans tend to drive between 95 and 115 mph, its why many engines in the UK feel flat.... get to 120 and suddenly everything makes much more sense, gear ratios and suspension set up start to behave...

as they built it to cruise at 120mph, why would anyone want to have the engine struggling at too low revs (causing engine damage, poor emissions and bad economy) by driving around in the wrong gear?

 

[LostKiwi]

There are relatively few sections of German Autobahns that are derestricted to allow that speed.

 

[TeddyRuxpin]

"There are more than 8,000 miles of autobahn in Germany, and about 70 percent have no limits on speed, according to the Federal Highway Research Institute, though other roads and freeways do have restrictions."

Other limits are 120km/h (74mph) and 110km/h (68mph).

Certainly, this weird '74mph to go into top gear' thing that's been applied since the emissions update is going to be much less noticeable for a German MB customer, than a UK one.

 

[JasonHookey]

Hi All,

I am absolutely livid with Mercedes (Harrogate mainly) right now and wanted to see if my problem is common before I explode! Found this thread so happy to post.

So I have a 2017 C250d 4matic, 9-speed gearbox. Lovely car, driver assistance package.....sweet. Got is as I live 140 miles from my office (yep, each way, don't ask) and wanted something nice but reasonably economic for the commute.

It was all going great until recently. Last service, they updated drive train software and engine management. Since this, when in automatic and cruise control at 70mph it won't go into 9th gear!!! My local dealership (Harrogate MB ) did some tests and said car was fine (although did almost no testing at 70mph) and that the car went into 9th at 76mph...which i pointed out was illegal!

So I did some further testing and it's weird. So using paddle shift I can manually go into 9th at 70mph and if I manually down-select to 8th the car RECOMMENDS I go into 9th! As soon as it drops back to automatic this up-shift recommendation goes and I stick in 8th. My local dealer said this was 'different software' using 'different sensors' but that seems strange to me????

They then tried to tell me it was the same economy - they'd done a test using a pump measure of fuel in, a drive (not motorway at 70mph I add) and then filled it up and calculated it. Since this came out at 48mph they were happy - me pointing out that at a 56mph average it WILL do 48mpg and my problem was at 70mph didn't land with them and they then told me the reading on the dash is not appropriate for measuring fuel consumption. I get it's an average and it's not 100% accurate but if I do the same drive, at the same time in comparable conditions 100's of times and since it now won't select 9th it's showing 5mpg lower, calibrated or not that large data set show's there is a comparative problem.

So to me it was simple - if the car, at 70mph is revving at 1800rpm for 2hrs in 8th on the motorway but I manually put it 9th and it drops to 1100rpm for 2rhs, this will burn the same fuel will it?? That's more environmentally friendly is it??? They are trying to fob me off and it's really getting to me.

The final thing is that apart from maybe 1 other person and me, this isn't a common problem to them.......so I want to test this.......

Please, if you have a similar 9th gear issue, can you please reply to this threat telling me what your issues are? I have no idea if I'll get anywhere but it possibly will (a) make me feel a bit better and (b) help me prove to Mercedes they have a real problem here.

Really long post for a 1st one but my blood is boiling here and I want to know if I'm nuts or I'm right and there are lots of us in the same boat!

Thank you for any advice or confirmation you've got the same problem.

Jason

 

[TeddyRuxpin]

Hi,

The OP and I pretty much summed it up and confirmed in our previous posts. It's not just the 9G boxes, my E350 with 7G and another E350 with a 7G+ box I've driven, do it.

If you go to 74-75mph it will change up. Or you can switch manually.

This seems to be happening to most MB with certain diesel engines, definitely all OM642 but also some of the 2L engines too, after going into a service. It's probably, in some way, supposed to reduce NOx emissions increasing CO2, by running the engine hotter (but also it will be increasing CO2!). And if you're in mainland europe, you probably won't notice it due to different speed limits.

MB don't/won't care. I thought it was DPF related initially as this is what happens when you are regenerated on the motorway. I took it back to them reporting higher fuel consumption and possible DPF problems, and they just said there was nothing wrong with it.

Good luck, if you get any positive response from them, please let us know.

Cheers,

Ed

 

[Bubble]

My 2014 E350 with the 9g box changes up to 9th @ 66 mph. according to the speedometer, which reads slightly fast compared to the GPS.

I'm going to avoid going to the dealer and avoid any updates!

 

[rf065]

Last service, they updated drive train software and engine management.

Just to clarify, that must be two seperate updates. Last time mine was in Mercedes I got the drive train update, mine will still go into 9th at approx 65mph. I won't be going back for the other update which must not have been available last time!

 

[TeddyRuxpin]

I believe it's related to the latest emissions software update.

I got one of these letters (attached) left on the passenger seat. My dad didn't, all he got was this note on his service statement... (also attached below).

Both are E350s with OM642, his slightly newer with a 7G+ box, both times the software was updated without clearly explaining the consequences (or wasn't even mentioned). He had a different MB dealer service his car.

 

[rf065]

I believe it's related to the latest emissions software update.

That's part of the problem with these cars, if you haven't been near a dealer for a while, you could be getting 3 or 4 updates next time you visit.

 

[TeddyRuxpin]

Indeed. However in my case, my car has a full MBSH and has been to the dealer a few times for other issues (gearbox itself was serviced by MB about 7-8 months ago), and it's only started doing it since this last time when this emissions ECU update was applied, so...

I wonder if it's part of some sort of passive regeneration thing. Otherwise, I can't see how revving higher at those speeds/moving the final gear shift point to 74mph will help with NOx emissions. But then, I'm not a mechanical and/or car ECU engineer.

 

[Gazwould]

My sympathy goes out to those ruined by the 'so called update' .

I don't get it , to produce less NOx , combustion temperatures have to be lower , hense the devil egr is deployed to inject excrement into the air induction with inert gasses and SOOT that doesn't burn very well to displace oxygen .

The result is horrendous soot related consequences , reduced efficiency etc but lower NOx .

Now the update is increasing revs and thus temperatures , so it doesn't compute !

Unless at these revs the egr is working four fold as similar with the VAG updates ?

 

[Rory]

So to me it was simple - if the car, at 70mph is revving at 1800rpm for 2hrs in 8th on the motorway but I manually put it 9th and it drops to 1100rpm for 2rhs, this will burn the same fuel will it?? That's more environmentally friendly is it??? They are trying to fob me off and it's really getting to me.

If it's 2hrs then is it that big a deal to just nudge it into 9th?

I do a long regular long stretch in a 40MPH limit in mine, I always drive in S mode (mine is 5 speed and has Standard and Comfort) - the car is in 4th and won't change to 5th until about 45 so I nudge it to 5th.

Even with only 5 gears it doesn't make much difference to the revs - does yours really drop from 1800 to 1100 from 8th to 9th? That seems unlikely.

 

[rf065]

If it's 2hrs then is it that big a deal to just nudge it into 9th?

I do a long regular long stretch in a 40MPH limit in mine, I always drive in S mode (mine is 5 speed and has Standard and Comfort) - the car is in 4th and won't change to 5th until about 45 so I nudge it to 5th.

Even with only 5 gears it doesn't make much difference to the revs - does yours really drop from 1800 to 1100 from 8th to 9th? That seems unlikely.

The problem with the 9 speeds, and I have two of them, is nudging them up a gear will not work unless they let you. Plus both the 8th and 9th gear are essentually overdrives, they will not let you change up manually at low speeds.

 

[Rory]

The problem with the 9 speeds, and I have two of them, is nudging them up a gear will not work unless they let you. Plus both the 8th and 9th gear are essentually overdrives, they will not let you change up manually at low speeds.

I did wonder about that, but the poster says he changed to 9th manually.

It would annoy me, for sure, but these things keep happening with emissions changes - like cars with AdBlue suddenly using loads more than was promised etc.

If it really does drive at 1100RPM I wouldn't be happy with that anyway - I have to nudge wife's Tiguan down a gear at 40 as it holds a higher gear than feels sensible, although its DSG box doesn’t have the fluid isolation a torque converter gives.

 

[Blobcat]

I did wonder about that, but the poster says he changed to 9th manually.

It would annoy me, for sure, but these things keep happening with emissions changes - like cars with AdBlue suddenly using loads more than was promised etc.

If it really does drive at 1100RPM I wouldn't be happy with that anyway - I have to nudge wife's Tiguan down a gear at 40 as it holds a higher gear than feels sensible.

Was around 250 revs IIRC between 8th and 9th at 70. It would sit at 1,250 revs at 70 in 9th, no power at those revs but it would do over 80mpg. I complained to my dealer that I could get into 9th manually and it would stay there but it wouldn’t always go there in auto. The box was very new at the time and lots of updates in 2017/2018 when I had services. Never fixed the not changing up issue I had and from what I’m reading now they’ve made it worse

 

[Eddie fh]

From now onwards will be servicing my own car where possible and things I can’t do will go to local indi , cancelled my service plan when I first read posts about this back in December, car goes out off warranty in March and cars already booked in for mot at indi and changed oil and filter early also did air filter because 4 years between changes for me is another merc con

 

[TeddyRuxpin]

FWIW on a 7G box, at 70mph it'll be just over 2000rpm in 6th and just sit there forever/until you manually change or go over 74mph.

In 7th at 70, it's at ~1650rpm which is way better for economy and fine for power.

I can manually go into 7th as low as 53mph and over, if I want to. So cruising at 60-65 should definitely be in 7th for economy - and that is what the car used to do before the update.

On a more economical E350 265bhp with 7G+ box, it's the same behaviour, but about 100-150rpm less.

Gearbox resets don't help.

 

[LostKiwi]

Don't always assume a taller gear is always more economical. I appreciate that the OP is seeing a difference but it's not always the case.

 

[JasonHookey]

Hey all,

Thanks for the replies. In short:

1. I can manually go up to 9th over 2hrs but in an automatic car that was £56k and less than 3yrs old why should I?
2. Yes, the revs drop and it makes a significant mpg drop as well.
3. My local dealership in Harrogate doesn't want to talk to me now since I've said I'm going to make this as public as I can. Even argued about putting it in writing!!!
4. The MB complaints process is 'ring the dealership and ask if I'm right'which seems less than adequate (local dealer manager even said that would happen)

The car is really poor now, MB are equally useless and honestly i will be selling asap.

Thanks all for the responses.

 

[ajlsl600]

think if i was HAVING to use dealer i would security tag the data port so they cant plug anything in without notifying me first.