Gbrewer

So over the course of the past week I have been noticing some strange trans symptoms. Here's basically the rundown... first of all I'm pulling out of my spot that I park in, next thing you know, I shift into drive and get a rough jolt once its in gear (no clank) then the car proceeded not to shift and I am stuck in 1st.

My immidiate instinct is to pull over, turn the car off and then try again, it worked. Then driving to work (40 mile commute) it does perfect until getting close to my work. While driving in the city I come to a stop and upon accelerating it stuck in a high gear, like 4th. I'm almost to work so I just shrug it off.

I then pull into my spot, put it into park, but then feel like I need to make a minor adjustment, so I then proceed to put it in reverse. Reverse is not working. I'm like screw it, I go inside and enjoy my 8 hr wok day. I end my day at work and drive home with no problems.

I absolutely love this car and it has been problem free over the past 4 months. The car has 104k miles but looks and runs great other than me having the replace the crank sensor and then now having to replace the can sensor. I tried changing the magnet other day and am still running with the CEL on that.

I understand that these cars transmissions are helped with a 39k mile tans service and am not sure when the last time it has been done, and I, myself, have not done it either. Are these symptoms common? And can they be cured with a simple drain, fill, and reprogram? Any help would be great, as I would love to avoid any serious problems like a balance shaft failure or trans replacement! TIA!

Gbrewer

Cam sensor... moto tab auto-correct + no edit lol

04mbc230

Just wondering. Are using S or C mode?

I have similar problems, but I only have it stuck on 1st gear, hence, limp mode.
I only have this issue when I am driving in S mode and usually I am suspecting it tries to bring it in first gear where the speed sensor don't like.

In C mode, I no issue at all.

Gbrewer

First time in c mode. Then s mode after restart with second symtom. Damn some cars lol

Gbrewer

From my research it looks like it could be a bunch of different issues. I think I probably have around another 6 months to a year at least left in this thing if I do nothing at all, and who knows how long if I reservice the trans. Worst case scenario, I can always purchase a low mileage trans for a grand or two versus opening this thing up and replacing anything, just seeing if anyone else has had any similar issues with easy fixes.

Glyn M Ruck

You need to see what codes you are storing. If you get the dreaded speed turbine code it is usually a conductor plate.

Gbrewer

Thanks for the input, I'll have to remember that when I take it by the shop. Thanks a bunch!

Gbrewer

Just drove a 500+ mile round trip with a little city driving all in S mode. No issues whatsoever... lol strange.

Glyn M Ruck

Conductor plate/speed sensor implausible issues can be sporadic. Sometimes they never develop into anything & on other occasions deteriorate.

SickSpeedMonte

I had the exact same problem. Mine started as your problem where you were stuck in high gear. That is limp mode, the trans will not shift and the torque convertor stays unlocked until you shut off/restart the car. It is a soft code. The hard shifting into drive happened to me after my car threw a check engine light, and at that point, a restart would not allow the car to shift. It stored a hard code that a shop had to clear. The code was for the turbine speed sensor (the input shaft speed). The sensor must be purchased as part of the contact board, and in some cases the contact board must be purchased as part of the entire valve body. I'm still a little unclear on what causes the VB to need replacing. I've heard it was a build date on a car that determines it, and I've heard that MB made a change that allowed the control board to be replaced seperately some time ago.

Now get ready for the best part.

If you have a turbine speed sensor code and you want to get it fixed (i.e. you are tired of limping across traffic to pull over and reboot your car), forget about your favorite independent shop. Mercedes will not sell these parts to anyone. They must personally diagnose, replace, and program the new sensor/contact board/valve body.

I was quoted $1200 for the contact board repair and $17-1800 for the valve body. That's where my car is now, and I'm driving my 13mpg $4/gal diesel pickup in the mean time. The indy shop I took it to cleared the codes and now MB says they can't find the problem and they drove it and it's driving fine. I know as soon as I pick it up it will do it. It threw soft codes (restart-able) for probably a month or longer, off and on. Sometimes it would do it once a day, sometimes it would be fine for 7-8 days straight. If you had it do it several times in one day, I'd say you are probably looking at what I'm facing.

Sorry.

Glyn M Ruck

Speed sensor quirks more often deteriorate into trouble on the 722.9 than the 722.6.

Especially true of early 722.9's

SickSpeedMonte

Wouldn't an '06 be a 7-speed 722.9?

LILBENZ230

Yes, but so are 07s in some cases.

SickSpeedMonte

Alright, im a bit confused now (but I'm also a bit burned out from coding the last few hours)

Do the OP and I have the same trans and same problem?

The SA just called and told me it's going to need a whole valve body at a cost of ~$1,875 and it's going to take until next week to even get it in.

1 year, unlimited mileage warranty. That will give me plenty of time to find just the right 6 speed vette.

LILBENZ230

Did he say why it would need the whole valve body? I had been under the impression the valve body thing was resolved by 2007 for the W203. What is your build date?

The 06 and 07s do have the same 722.9 transmission.

Glyn M Ruck

Sorry SSM - I'm a dick - I saw 2002

SickSpeedMonte

He didn't say why. I just called him back and he said that he wasn't really sure and that he was going to ask the shop forman. He said the forman was absolutely sure it needed the entire valve body. Sounds fishy... he said the only code was the turbine speed sensor as far as he knew.
take it easy Glyn, no big deal

https://mbworld.org/forums/c-class-w...restart-2.html
Wanted to link these related threads together for anyone searching in the future.

LILBENZ230

The conductor plate is a known weakness with the 722.9 but the valve body thing isn't on the 07s..

SickSpeedMonte

He called me back and said that it's still not certain as to whether the entire VB will be replaced... they are apparently waiting on MB to make that determination based on the software version and the VIN or maybe the serial # of the VB. So there's still hope that it could be a $1000 repair instead of ~$1900

LILBENZ230

You'll probably be fine with a conductor plate. Sucks either way at less than 100k miles. Really no excuse for it.

SickSpeedMonte

I'd think so too, but it sounds like I don't have much say in the matter if I want the car fixed.

LILBENZ230

This should never be the case. Ridiculous.

SickSpeedMonte

Got word yesterday evening that they will just be replacing the contact plate for $1,050. So that's good news if there is any to be had here. It should be done today, but the dealer is probably ~50 miles from my house and I have no way to get a ride there any time soon.

clifton001

Same thing happened to me last month my dealer replaced the conductor plate (bs Mercedes should fix it for free very common issue) and they replaced my balance shaft and cam solenoids for free said Mercedes extended the warranty. Might want to have them check that out as well

Glyn M Ruck

Clifton. Welcome - what mileage?