TheBigM1996

Hi everyone!

I've been lurking on this forum since the idea of getting an MB crossed my mind, but this is my first post.

Some context: I bought a 2011 W212 4MATIC Wagon (722.9 transmission) in (theoretically) great condition with 93k miles about three months ago (August) from a Mercedes dealership in the Bay Area. Twenty minutes after driving off the dealership, I got a check engine light. The car was running fine; I came back to the dealer, and they ran some tests. Turns out cylinder 3 had a misfire. They told me it could be a fluke, reset the codes, and sent me away to see if it would happen again. So far, no more problems with this.

I put something like 1.5k additional miles on the car with no further issues and couldn't be happier with it. After that trip, I decided to do a full service on it, as the dealership didn't have data on when it was last done.

I took the car to an independent mechanic (end of August) in the Bay Area who was recommended by the owner of a small dealer. He quoted me $1.4k for all the fluids (transmission, engine, coolant, differential, brakes), their filters, a cabin filter, and a general inspection. After getting this done, the owner told me the car was in great shape.

Shortly after, something weird happened. I drove to Costco, parked, shopped, and when I drove off the lot with the car oil temp still around 80 C, the car drove fine but didn't shift gears. I noticed this on the highway, and since I couldn't drive fast enough as the RPM was as high as it goes, I stopped on the side of the road, restarted the car, and suddenly, the car was shifting normally again. No check engine light whatsoever. I drove home, and the next day I called the independent mechanic. He told me to come back to the shop after the weekend for a diagnosis.

After driving for the weekend with no issues, I came back to the mechanic. He did the diagnosis in front of me and showed me the codes. I don't remember exactly what they were, but they related to faults from the speed-reading sensors and transmission valves. Since this had only happened once and after restarting it went away, he reset the codes and told me to come back if it happened again. He also mentioned that this might be due to an electronic problem and that it shouldn't impact any other component.

Then, for the next month or so, the car drove fine, and the transmission issue didn't happen again, or if it did, it was so sporadic and easy to temporarily fix that I didn't pay much attention (life was very busy during that time). What I did was buy an Autel AP200, as the suspense was killing me. After running a scan, I got the following error codes:

• 0632 Combustion misfiring has been identified
• 0644 Combustion misfiring in cylinder 3 (the same problem I had at the beginning of my ownership)
• 2725 An electrical fault exists in the pressure regulator valve 5.
• U144500 Data received from the lower control panel (LCP/UBF) 2 were implausible.
• D691 An implausible wheel speed signal was received.

I also managed to plug the Autel and get live data when the problem is happening. What I observed is that it says the transmission is in Drive and "unknown gear", and when I restart it and it works again, it says 2nd or 3rd or whatever.

THE ISSUES:
In the third month of ownership, I started experiencing this problem more often:
I'd turn on the car, let it run for some seconds, and then when shifting into Drive or Reverse, it would shift harshly into gear, shaking the car (both Drive and Reverse), and although drivable, the car wouldn't shift gears. I could still shift between N, R, P, and D, but whatever gear it shifted into when put in Drive, it was stuck in that one (sometimes it felt like 2, sometimes 3, sometimes 1). This issue was normally solved after restarting the car, and then it would drive normally.

And weirdly, I normally don't have this problem when the car is cold (as cold as it gets in the Bay), but if I drive to the gym, work out for about an hour, and then turn on the car again to come back home, with the car still more or less warm, then I'll get the issue.

I took the car back to the Indy shop, and after confirming that the transmission fluid level was correct, he ran the diagnostic tool, gave me more or less the same codes I got from the Autel, and performed a transmission adaptation reset. He told me that, as it was happening more frequently, this would end up needing a transmission conductor plate repair, with an estimated cost of $1.4k, but he couldn't perform this now as he needed to schedule a specialized guy to come and do this part of the repair.

I also called the dealer to ask about this, and they told me to bring the car to them, pay for 2 hours of labour, and they would check the issue.

On top of that, and to get a third point of view on the issue, I took the car for inspection to a (sketchy) Mercedes shop close to where I live, and this is where the bad news started. They inspected the car today and told me that when they took the transmission pan out, it had some graphite and metallic dust in the transmission fluid (despite it being very clean and at the correct level), and they observed that the clutches in the transmission were worn down and that the car would probably need a full transmission replacement. They said that a valve body repair wouldn't fix the issue. This transmission swap would cost me around $12k. After this terrific news, I told them to reassemble the car and I drove home (with no shifting problems).

What am I supposed to do now?
I'm thinking about taking the car back to the dealership as they assured me when I bought it that they had inspected it deeply and didn't find any problems with it (and if they had, they would have auctioned it).
The other option is to get it to the first independent shop to also perform a check and get a second opinion about the transmission state.


blissful ignorance

CaliBenzDriver

You've purchased a now 100kMi E350 S212 M272 MY'11 from a local MB dearler that has given you all sorts of troubles from misfires to transmission not shifting.
You've had quite a few shops look at it with conflicting opinions mostly regarding tranny issues.


Ok, let's have a good look at the fault report: do you notice the word : >> STORED <<

This means the faults are transients and not current at this time. This is pretty good news because I don't see any current faults.

You did well with your decision to get fluids replaced at a semi-specialist shop. You can trust proper fluids were used. What color is your coolant fluid? (Pls don't say GRN!)


> Scanner 101:
Once you have the present report saved you go ahead an clear faults to reset crazy modules else they may not play well.

Next you drive for a while and scan again.... this is like fishing for lobsters. You set baits and wait a while for stuff.

That's the way you see what faults keep coming back - Those are usually meaningful.

> Keep an eye on engine oil (5W40) if your engine drinks quarts of it.

+++ Are your rear suspension AIRMATIC leveling... ok??

S-Prihadi

Its is so common occurrence it seems now that I hanged out at W212 section for 5ish years, I am seeting a pattern

01. Someone bought a used W212, of age 8 to 13 years , today.
Mileage above 75,000 miles.
He or she would usually be the 3rd owner, not 2nd owner.

02. The now then new 3rd owner replaced the tranny fluid.

03. And then................ tranny starting to misbehave a bit for the unfortunate 3rd owner.

I said unfortunate 3rd owner, is when the 2nd owner does not give a rat-azz doing tranny oil change per maximum 3 years and/or 30,000 miles whichever comes first.
Tranny oil change when done by MB dealer is not cheap, so I suppose 2nd owner could ignore proper tranny oil + filter replacement.

1st owner if sold the car within 3-4 years, wont touch tranny fluid at all. 5 years or 75,000KM / 46,000 miles is what MB Indonesia use as service interval.
I do not know what is the US version tranny fluid replacement schedule, I bet it is more mileage aka more azz-hole.

.
If anyone pay close attention to the amount of "dirt" the 2 magnets inside the tranny oil pan even after a mere 10,000KM or 6,000 miles, imagine tranny oil
of 50,000 miles of dirt not caught by the magnet, but reside at the solenoids and other small passages.
Our tranny is basically a wet clutch tranny, so many clutch pack.... 4 set. Clutch K3 is the *****, it get bang-bang-ded in almost any gear, except at 4th gear.





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I hope OP's tranny wont cost him much $$ to fix.

Andre Cateb

Look, once a friend of mine had a transmission issue with similar symptoms to yours in a W204. But it's very important to look at the correct messages from Xentry. What you are experiencing seems to be the loss of the gear selector position sensor. The TCU doesn't know the position of the gear selector actuator and goes into limp home mode and looses the ability to use the adaptation values (hard shifts). His problem only occurred when the tranny was already hot and was clearly an electrical issue. A new conductor plate (or a specialized repair on it) should solve it since it shifts fines when the issue is not present.

One point that it doesn't makes sense is that you don't reset adaptation values from the transmission unless you have refurbished it (replaced clutch packs).

P.S. You cannot see the clutches without completely dissembling the transmission. They are just not visible if you only remove the oil pan and valve body, you need to really disassemble it completely. so I have no idea how the last shop concluded they need to be replaced.

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TheBigM1996

Hey Andre, thanks for the message. The Mercedes specialist told me that the issue will most likely be fixed with a conductor plate rebuilt or replacement, and that´s more likely what I´ll end up doing to it. The car is in the dealership where I got it for diagnosis until next week. I´ll share any updates once I get it back, but I bet that I´ll end up going for a conductor plate fix.

TheBigM1996

Hey CaliBenz,

I have deleted the fault codes in the past and the ones I posted are the ones that came back. So far, I didn't notice any oil consumption from the car, and I can check the coolant colour once I get it back from diagnosis.
The AIRMATIC levelling has worked fine so far. Only when I put or move weight on the back with the car off it gets low, but uniformly on both sides. When I turn the car on again it rises without a problem. Should i worry about this as well? 😅

CaliBenzDriver

Worry not, maintain yes!

> AirMatic...
I am not an AirMatic guy... I know compressor creates condensate that rust valve body - So make sure leakage is low to keep condensate production low as well.
A lot of people endup deleting their air suspensions out of cost being upside down. Keep chances on your side before end.


> STORED... Interesting :
If these stored faults are recurring that means they are live transient conditions. Not old faults generated by low battery crank.

Then you'll want to adress them on your own agenda before they mature into something more challenging.



++++ TCU focussed:

genuine concern

See if this exact same fault keeps returning reliably after couple driving cycles.
If TCU report other faults or this one doesn't always materialize then it'll be positive news.

Engine ECU complains of misfires which are not show-stopper like tranny limp-modes.

TheBigM1996

Just to clarify the problem again: sometimes, when i turn the car on -> shift into drive -> harsh engagement -> can drive and change back to P, N, R, but it wont change gears. If the last time it was in 1st, i´ll remain in shifts. The car doesnt know in which gear it is (nor automatically nor paddle shifters) - > turn it off and on again -> problem dissapears 90% of the times

Update from the dealership mechanic:
I dropped my car off today and they told me they were going to try several times to turn it on, let it sit and turn it on again to see if they could reproduce the error I was describing, saying that my car will stay with them until Monday or so. I went to work and 3 hours later I got an estimate for all the work they believed my car needed:

• $5k to fix a rear main oil leak, and this is the photo they sent me. To be honest, and as the metal sheet below seems to be completely clean, i wouldn't consider this a problem that needs to be fixed immediately, but what do you guys think?

• $4.5k for a valve body fix/swap. Again, taking into account how little time it took them to diagnose this, I´m not too confident they actually investigated this and they are just using sledgehammers to crack nuts. I asked them if they think they could just change the conductor plate, as when the car engages correctly into Drive it shifts and drives fine for as long as it is on, but they told me that they don't do that.

I´m kind of speechless again. Next week I´ll get the car to the Indy shop again to reevaluate all of this and get a final, third opinion. If he agrees that just a conductor plate could save this car I´ll guess I´ll bite the bullet and pay the $1.6k he quoted me for that job.
Do you guys think this is the correct course of action? Should I try fixing this car or is it going to be a money pit?

ChrisHimself

don't trust your dealer. I used to be one of them. you will spend the 4.5k just like everybody else and then it ended up just needing a transmission service or two.

thats not a rear main seal leak thats pooled oil, it's not fresh enough to be the origin point, check your oil cooler, cam magnet, and cam position sensors.

believe it or not if you change the fluid again and clear the codes it would help. The "goo" conducts electricity and it builds up and is abrasive and if were in the habit of throwing money you might as well attempt one more transmission service. You should use 7L, 5L to fill, and 2 to "rinse" which is where you overfill it and let it come out. Since the transmission wasn't rinsed all the dirt and old fluid from the last service sorta just mixed with the new batch and if its exceptionally dirty you could cause issues, and well.. I suspect you are the first transmission service just like every other car at 100k I've seen.

The speed sensor is when the fluid isn't working properly or the filter is jammed up and you're not getting enough line pressure so the output and the input speeds see a variance and well, here you are. That limp mode makes the transmission refuse to shift. A TCU/plate CAN have these issues but usually I like to really make sure that service was clean and the correct fluid was used (A89 if applicable uses the blue stuff)

I'm local to you, Alpha European Autotech. I don't need the business I'm actually full for two weeks but if you have any questions call the number in the link and I like helping out aorund here.

CaliBenzDriver

FYI: MB are money pits only if you let them. They don't have to be!

I am optimistic with the way chaos goes away when you restart. It sounds like soft-crashed ie. old-fashioned disruption.


The PRND situation is usually associated with ISM + SCM Modules, not the tranny itself.
This takes place mostly when you try to shift out of Park, then nothing happens.
IC Display then looses track of PRND selection... is a sign of that.


"Valve body" controller aka. "conductor plate" is gives poor shift qualities while driving. (You did show a stored fault with that unit).


Right now cosmetic oil leaks are not the top priority until you can sort out No1.

When everyone you talk to want to jump to new XYZ, you've got to stick with reality - Listen to what your scanner is reading to guide your troubleshooting.

Chris down the street from you could be your ticket ✌️
100k for these cars is all right so long you call the right shots.

Andre Cateb

My opinion is that the rear main seal is easy to diagnose and time consuming to fix. If it's not dripping all over, it won't have any negative effect. I would only attack it after the transmission issue is resolved.

MB sometimes have parts that are only sold as assemblies. The oil cooler on the M271 is one I can remember. You could buy just the oil cooler from sites like FCP Euro, but on the dealer it is only available as an assembly together with the oil filter support. This might be the case with the conductor plate.

I believe that if any Indy shop in your area is able to replace or repair the conductor plate would be a more cost effective solution. One last piece of advice would be to ask the dealer (or any of the shops you used) if they ran the Xentry and what exactly was the failure message recorded on the TCU. Xentry saves a "photo" of the time the failure occured (freeze frame) and some valuable data can recovered from it. It might help pinpoint the failed component within the transmission electronics.

Hope this helps.
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ChrisHimself

You don't need to change the oil cooler, it has a housing gasket and the actual cooler gasket to the block which conducts coolant and oil at the same time. Use Elring or Mahle for parts. If you want to commit to a full housing, it's Mahle-Behr. I'm fairly certain this is your leak.

Once this transmission pickle gets figured out I'll take care of your service if you decide to keep the car. I learn most of my Mercedes repair from this forum actually. I'm only two years into business and I'm solving tons of these kind of problems thanks to the guys here.

It's a really reliable car they sorta just get trashed on by cheap people which ends up messing with the electronics because of grit/conductivity. The thermostat gasket usually is the next item to go out. All of my cars have been running beautifully. I would attempt ONE more transmission service and then go the conductor plate route. Your car has to be pretty abused to need a plate at this mileage, I'd usually check solenoid screens for debris and INSPECT the valve body for erosion but I understand nobodys doing that for free.

As for your stored misfire codes, you can honestly have those if the car hasn't been run in a while. I'd keep an eye on it and ponder plugs. I dunno how much you can DIY but the plugs are not bad at all on this car.

Conductor plate repair, you're doing a transmission service and then removing the valve body and solenoids to free the conductor plate. You can't replace these because it has to be coded to the ECU/Chassis so we do actual repairs on the plate itself. HOWEVER, if you do have a TCM issue, you would have more error codes typically in my experience ranging from every speed sensor not giving a signal. As for the repair, if you can get the TCM out, you can send it to these guys

It could be something as simple as the wheel speed sensor not being plugged in all the way. You can actually have transmission issues from this.