B Class CVT Transmission Failure

[ssldn]

I am currently looking for a 2009/10/11 B200 CDI CVT. Most of these comments relate to older models, does anyone know if the CVT box was improved after all these issues?

 

[mercbclass]

Hi,

I have had exactly the same problem with my Mercedes B200 (55 plate).

The car has been recovered to a garage but I'm worried that they might try and rip me off. The AA said that it appears to be the "gear selector" and when they checked the transmission oil, there was hardly any in there.

Sr2 - what was the outcome of yours?
Thanks

Hi

Unfortunately 2 weeks ago my B200 Turbo popped up the message "Transmission Fault". The car was still turning over but there was no power going to the weeks (drive or reverse). Pulled over waited a few minutes and restarted but still nothing but a "crunching" noise when I put it into drive or reverse. Recovered to my house.

I have a number of questions which I hope someone can help with?

- Difficult one but any ideas what it may be?
- Anyone else ever experienced this?
- Any ideas of cost to sort out?

I have spoken to several indis and they tell me that MB are the only people to sort it out as it is a CVT. Is this correct?

Spoke to MB and they told me it would cost £180 to diagnose! :-(

The car was bought for my wife to take the kids to school so not abused at all. It has FMBSH with 37000 miles and 06 plate. Is type of fault common at this age? Mileage? Do I have any leverage against MB for this?

Sorry for all the questions as I am a bit distraught. I lost my job so don't have much money at present and it is the only car we have so having to rely on friends and family for lifts :-(

Any advice will be really really appreciated!

Thanks

 

[Snake75]

@arjaffer
I currently have exactly the same problem as you had (continuous whirring noise) on my B class 200T CVT with only 77 000 kms (48 000 miles). "Bravo" for your perseverance and tenacity. I'm just starting the procedure : I'm writing a letter to MB France (I'm from Paris). I hope to have the same result as you had.
Thanks for having shared your full experience

 

[peapod]

my A180dci started playing up at 31k. eventually after pleading with the dealer they agreed to change the gearbox oil and charged me £207. That cured it. so if you want to sleep at night I advise get merc to change the oil every 30k. Mine has doen 57 now and still behaving but it will get a change at 60k. The refuse to decrease the change interval and admit it needs it.

 

[jamcasey]

I have a 60 plated B180 CDI CVT and am going through the same thing, it has 36500 on the clock and has been well looked after. I bought it 2 yrs ago from a MB specialist NOT a dealer and last week I got the "transmission" fault come up on the dash. I took it back to Simon Light Mercedes in Ware and they said it could cost from £1400 for gear box electronics to £5000 for a gear box re build but they would not know until they dropped the box out. I have asked for a contribution towards the cost as I said that a major vehicle component should not give up after just 36500 miles. They said no and I should take it up with MB. Any advice? I now I will have to take it to MB first and get them to check but any advice will be most welcome. Thanks in advance

 

[wongl]

This thread may of relevance to B-Class CVT owners. For those who have managed to change their transmission oil, removing the transmission ECU might be within technical reach, in which case send it off for diagnostic might be a cheap option to eliminate a faulty ECU.

http://www.mbclub.co.uk/forums/engine/191266-w169-auto-transmission-fault.html

 

[peapod]

hi Wong

i have a A180cdi cvt, at 25k it played up, ratio got stuck joining the motorway I slowed down and increased speed again and it cleared. MB had it or a week and I think they just drove ir hard. I got them to change the transmission oil at the time, they did not want to do it. No problems since. Now at 53k i noticed at crawling speed in slow traffic that pick up from stationary is becoming a tiny bit jerky. I am going to get MB to change the oil again and comment on the behaviour as a precaution. A bit anxious about it and would chjange the car but wife and i both love it.

 

[wongl]

hi Wong

i have a A180cdi cvt, at 25k it played up, ratio got stuck joining the motorway I slowed down and increased speed again and it cleared. MB had it or a week and I think they just drove ir hard. I got them to change the transmission oil at the time, they did not want to do it. No problems since. Now at 53k i noticed at crawling speed in slow traffic that pick up from stationary is becoming a tiny bit jerky. I am going to get MB to change the oil again and comment on the behaviour as a precaution. A bit anxious about it and would chjange the car but wife and i both love it.

There is a common (but easily fixable) problem with the Transmission ECU (sometimes referred to as a TCU) from the autoboxes of W168, W169 and some B-Classes. Sadly MB dealerships are unaware/does not endorse repairs to these types of faults in the TCU, instead offering to replace with a brand new TCU that has to be factory ordered and coded to the car. The cost of the new unit plus the prohibitive MB labour rates typically make this an unaffordable repair - often costing what the car is worth. This creates a poor reputation for second hand W168/W169/W245 etc, but it creates a great opportunity for someone to pick one up as a real bargain to fix up.

Essentially the fault manifests in one or more of the connecting wires breaking loose/off from their connectors on the inside of the sealed TCU. This results in an intermittent bad connection(s). A typical symptom is a random transmission fault that can be cleared by switching off the engine.

When the car exhibit these symptoms, it is essential to get a STAR diagnosis to help determine the likelihood of a bad connection in the TCU or something else. Intermittent connection problems typically result in at least one fault code associated with more than one faulty solenoid valve together with an improbable signal fault of some sort. Here are the fault codes that were repeatedly recorded on my faulty TCU -

1634-Component Y3/9n1 is faulty...,
0793- RPM signal Y3/9n1 is not available...,
0722- RPM signal Y3/9b5 is not available...,
0896-Impermissible adjustment of the step down ratio...

According to ECU Testing, this fault is most likely to occur to a gearbox when it has covered or exceeded 80,000 miles!

As one can imagine, the probability of several components failing all at once is extremely small, although not impossible. This, coupled with the fact that the transmission appears to be capable of performing normally following a restart would further support the case of a bad connection.

Some members of another forum have reported that they have successfully completed DIY repairs on the bad connections on faulty TCU by cutting access "windows" through the TCU case and then re soldering the broken connections. I would not recommend anyone attempting this unless they are extremely skilled with cutting and soldering as damaging the TCU could result in an expensive replacement from MB. Furthermore there is a debate regarding the "best" solder to use for such repairs - the solder needing to be flexible due to the vibrations in the gearbox, yet tough enough to withstand the high temperature inside the gearbox.

Personally, I think sending the TCU off to be tested by ECU Testing is a safer approach since the unit will be tested before they will undertake any repairs. If the unit is faulty and repairable, the £230 is well spent plus you will get a lifetime warranty from ECU Testing. If the unit is not faulty you will get peace of mind for circa £50.

The good news with the MB auo gearboxes is that the electronics often shut down the box before any catastrophic mechanical fault develops. Sadly the clever electronics cannot save the gearbox from faults caused by wear and tear or lack of maintenance.

 

[MB-BTurbo]

Hi everybody

Sorry but I was not getting notifications of post on this thread. Basically Mercedes were actually quite good. Cut a long story short. They gave me a hire car while they repaired the drive shaft.

They told me the cost was £750 for the drive shaft and £750 for the labour! But as a goodwill gesture they would only charge half price for the drive shaft and free labour. So all in it was a lot better than I thought but still ridiculous that the drive shaft failed after 37k.

Cheers

Is it me or does this seem a concerning price for a driveshaft? I was quoted £250 parts and labour for mine (from an indi), which as it turned out didn't need doing anyway . How can there be justification for charging £1500 for the same thing?

 

[MickyP64]

I have a 60 plated B180 CDI CVT and am going through the same thing, it has 36500 on the clock and has been well looked after. I bought it 2 yrs ago from a MB specialist NOT a dealer and last week I got the "transmission" fault come up on the dash. I took it back to Simon Light Mercedes in Ware and they said it could cost from £1400 for gear box electronics to £5000 for a gear box re build but they would not know until they dropped the box out. I have asked for a contribution towards the cost as I said that a major vehicle component should not give up after just 36500 miles. They said no and I should take it up with MB. Any advice? I now I will have to take it to MB first and get them to check but any advice will be most welcome. Thanks in advance

That all sounds very expensive - £1400 is about the cost of a complete valve body replacement.

Common problem is the speed sensors connected to the ECU, you can either choose to get that repaired (by someone like ecutesting) or replaced - MB now supply the ECU separate to the valve body so you don't have the expense of paying for the whole lot (think it's about £300 - £400 for a new ECU)...£5000 sounds more like the cost of a brand new gearbox!...had to get mine rebuilt recently - it cost half that...

 

[M77]

There is a common (but easily fixable) problem with the Transmission ECU (sometimes referred to as a TCU) from the autoboxes of W168, W169 and some B-Classes. Sadly MB dealerships are unaware/does not endorse repairs to these types of faults in the TCU, instead offering to replace with a brand new TCU that has to be factory ordered and coded to the car. The cost of the new unit plus the prohibitive MB labour rates typically make this an unaffordable repair - often costing what the car is worth. This creates a poor reputation for second hand W168/W169/W245 etc, but it creates a great opportunity for someone to pick one up as a real bargain to fix up.

Essentially the fault manifests in one or more of the connecting wires breaking loose/off from their connectors on the inside of the sealed TCU. This results in an intermittent bad connection(s). A typical symptom is a random transmission fault that can be cleared by switching off the engine.

When the car exhibit these symptoms, it is essential to get a STAR diagnosis to help determine the likelihood of a bad connection in the TCU or something else. Intermittent connection problems typically result in at least one fault code associated with more than one faulty solenoid valve together with an improbable signal fault of some sort. Here are the fault codes that were repeatedly recorded on my faulty TCU -

1634-Component Y3/9n1 is faulty...,
0793- RPM signal Y3/9n1 is not available...,
0722- RPM signal Y3/9b5 is not available...,
0896-Impermissible adjustment of the step down ratio...

According to ECU Testing, this fault is most likely to occur to a gearbox when it has covered or exceeded 80,000 miles!

As one can imagine, the probability of several components failing all at once is extremely small, although not impossible. This, coupled with the fact that the transmission appears to be capable of performing normally following a restart would further support the case of a bad connection.

Some members of another forum have reported that they have successfully completed DIY repairs on the bad connections on faulty TCU by cutting access "windows" through the TCU case and then re soldering the broken connections. I would not recommend anyone attempting this unless they are extremely skilled with cutting and soldering as damaging the TCU could result in an expensive replacement from MB. Furthermore there is a debate regarding the "best" solder to use for such repairs - the solder needing to be flexible due to the vibrations in the gearbox, yet tough enough to withstand the high temperature inside the gearbox.

Personally, I think sending the TCU off to be tested by ECU Testing is a safer approach since the unit will be tested before they will undertake any repairs. If the unit is faulty and repairable, the £230 is well spent plus you will get a lifetime warranty from ECU Testing. If the unit is not faulty you will get peace of mind for circa £50.

The good news with the MB auo gearboxes is that the electronics often shut down the box before any catastrophic mechanical fault develops. Sadly the clever electronics cannot save the gearbox from faults caused by wear and tear or lack of maintenance.

Question: There are 10 bolts holding the valve body on B200. In order to remove the valve body to access ECU, does the connector have to be disconnected from the housing?
If yes, any good suggestions to remove the connector?
Mike

 

[zipdip]

The cvt box when first designed was a great idea,and was almost bullet proof,but car manufacturers are well known for taking the cheapest route and so the boxes are prone to a number of faults,Mercedes are no exception,the B class,is a great little car as a manual but anybody who knows about cars steers well clear of the auto ones,of course it does not help those members who have one,many of the faults are electrical,as is the faults on S class cars,at least there are solutions and at a cost not to horrendous.

 

[Benzowner]

My 2007 B180 Cdi with CVT box is just coming up to 100k miles, as yet, touching wood , no problems.

 

[M77]

Question: There are 10 bolts holding the valve body on B200. In order to remove the valve body to access ECU, does the connector have to be disconnected from the housing?
If yes, any good suggestions to remove the connector?
Mike

OK. The connector has been removed.

 

[eric990j]

Cvt connector

Hi, where is the connector, is it accessed from inside the engine bay?

Hope you can help

Best regards

 

[Zhars]

OK. The connector has been removed.

Im facing the same issue with the connector. How did you manage to remove it?