Alright. I got my first experience in limp mode.

Happen just right after I got off the freeway and stop at the first light. After the light turns green and I gas it a little. All I got is a high rpm and the car just rolls slowly. I was like, wtf?? Gas it a little more and still nothing but high rpm. I shifted it to Park and then back to D. Upon doing so, there was a jerk. When it was on D, I gas it and still nothing but high rpm.

I parked to the side and it dawn on me that the car is in limp mode. No lights in the dash board and no indication of what had happen to cause this. As remember reading many treads in this forum, I turned of the car completely and reboot (computer term, haha). That did the trick, the car went back to normal. Didn't have any issue since then.

I know this is up to no good, so I contact a MB dealership and asked about why it went into limp mode. Was told to bring the car in to diagnos. Did that the next morning and they told me it's the speed sensor that is acting up.

I read some issues with the speed sensor, but don't recall that this occurs on the 2006 and up. I thought they had corrected this issue with the speed sensor being too lose and held by only a few contact.

With that in mind, do I just have them just replace the speed sensor (conductor plate (plastic part))? Or should I just get the whole kit and replace the conductor plate and also the valve body (aluminum)) as well? Heard this part is on top of the transmission and that is probably the main cost in labor. Don't think I want to revist this issue again.

Any suggestion as in terms of cost and part to replace?

Oh, they said, this can't be done without MB shop. Has something to do with security code on it?? Is this true?

Glyn, any suggestions?

Man, this car's tranmission issue is just eating me alive. Also, I am worried about the other big issue with this car. The chain sproket where it has something to do with the balance shaft. Man.. I think I need to get some form of extended warranty on this car as insurance, but that would be on another topic.

Guess the caused of it:
I think I have an idea how I got this issue. I usually and have always drive on C mode. Before I went to put some gas that morning, I decided to put it in S mode to stretch it's leg out. I guess that was a bad idea. I also put some chevron fuel injection bottle in the tank durning the fill up. I doubt the fuel injection bottle has anything to do with it, but just making some notes what had transpire that morning. I have a feeling it's the mode switch and the car didn't like it or perhaps that was the treshold prior the speed sensor gave way.

 

On a 722.6 5 speed the speed sensor issue would usually mean the conductor plate. On a 722.9 7G it usually means the entire electrohydraulic valve body. Benz won't even let their dealers work on the 7G valve body. It has to be repaced complete from Germany. Benz knows they had speed sensor trouble on early 722.9 transmissions. I would approach MBUSA for a co payment at minimum.

 

Yeah its a whole unit, I've seen conductor plates order but like glyn says only for 5 speeds.

Btw I wouldn't waste the time trying to go through MB usa, they won't good will work on a car thats 2 years out of warrantee.

Has the trans been flushed regularly and you have proof? Id possibly take that to the drive manager or director of the dealer your going to and complain, but it depends on how much they want your business if they want to discount parts or labor. You could ask if they are MBOC participants that will save you a bit like 20 percent most places.

Good luck

 

Glyn is right. Generally speed sensor issues on the 7G require full valve body replacement. But, depending on the exact DTC, they will sometimes replace just the contact plate. Your dealer should have said what exactly they would replace based on the DTC.

Second, the security code that you talked about, is not entirely true. What it is called in online SCN coding. When the new valve body is installed, it needs to be coded to the car with a STAR diagnostic that has online SCN coding capability. This generally means dealer only, but many indy shops have this capability.

Look back at my thread, and you will see I had the speed sensor issue with limp mode as well. My symptoms were a little different. Dealer said my code required a valve body replacement at close to $2000 complete. I just decided to keep driving it until it happens again.

Oh, and when I contacted MBUSA to see if they would help cover at least some of the cost since this is a known issue, I was told sorry, I was on my own for the repair costs.

 

MB USA will usually make a plan if your mileage is not over 100K. They replaced Karo's EHU free of charge. Goodwill takes many forms with MBUSA. Be polite but firm.

EDIT: Sorry - John and I posted at the same time. MBUSA seems to be inconsistent in this regard. We have an MBUSA employee who is fairly senior on the CLK forum who shall remain nameless at his request. I am repeating his advice.

 

I have the same worries about the 722.9 transmission and the balance shaft sprocket, and have done a lot of research on these subjects.

There are shops out there that can rebuild 722.9 valve bodies, but Mercedes has started blocking them. For some reason Mercedes wants all 722.9 valve body issues to be dealt with by dealers. Even if you are paying out of pocket, an SA needs to provide them with diagnostics and paperwork before the part can be ordered.

Check here: http://www.beckmanntechnologies.com/index.php.

You might see if they can help if Mercedes doesn't.

 

alrite so my car shifts hard to begin with and now im having issues with the overall tranny. ESP off, Stepstronic off.. etc etc. So my question is my transmission always shifted hard. is that from a bad conductor plate or a valve body. Because if they says its a bad conductor plate and they are right near the valve body i might as well have them replace the valve body as well?

 

It might just be the conductor plate, It might be the shiftplate/valve body. There might also be some clutch damage on your box causing shift shock.

The conductor plate is cheap - The whole valve body has to come off to replace it. The valve body is damn expensive on a 722.9.

Do you have an extended warranty?

 

Drove a '09 C230 W4M - no problems (must be lucky), got itchy and upgraded.

2012 C300 in the shop since Monday. SM managed to replicate hard gear shift - they tried new SW updates for torque converter, etc. - no joy.

They've just ordered a new valve body.

Just 5 weeks from in-service date and I'm car-less!!

Let y'all know how it goes when I get it back.

 

cn an independent mercedes mechanic do the repair work on these or is it dealer only ?

 

Mine was done at dealership, they fixed it with new valve body (ECM).

 

how long ago did you have it done and do you remember about what it cost to do and how long it took?..thanks!

 

About a month ago - no charge under warranty. SM confirmed the hard shift, flashed new firmware to fix a torque converter issue but MB Canada would only dispatch the replacement ECM after the pressure readings were downloaded to them.

About a day for the troubleshoot/FW and pressure readings. 3 days for part to arrive and a day to install/test. Had to get a service loaner.

 

I have a 2005 e500 with 63000 miles, and have been reading much about the transmission issues. I have had two adaptations and still experience what is at times a hard shift into and out lower gears. The problem is more prevalent when the vehicle is "cold". I have a couple questions:
1) what could be other (hopefully less costly) issue?
2) if I do need a valve body and have less than 100k miles how do I contact mbusa to ask for assistance?
3) my vehicle hasn't gone into to limp mode, but can any major issues form with not having a 100% valve body (if that is what it is)?

Also, I have also read you MUST have a full transmission service. I am not certain if mine has ever had one. Would this be recommended? What is generally involved and a price point? I have also read that it is not advised to have what I can term a "forced flush". Is there any other kind?

Thank you!

 

I am having the same issues with my 07 R320 and 7G. My vehicle only has 55,000 miles. Surely it would be a candidate for MB assistance. Perhaps we need to get some government over-site into this issue. This frequent of a problem sounds more like a design flaw than wear and tear.

 

Hi, I have a CLK350 2006 and I'm experiencing the limp on the transmission. Any idea how much does it cost to replace the valve body?

 

I have an 05 clk500.
The tranny wont shift past 2nd gear I think. The check engine light code shows P0717. From my research on these forums and others it appears I will have to change the conductor plate and/or the valve body.
Would it make sense to just change the entire tranmission?
I can get a used transmission fairly cheap but am worried that if it's installed by someone other than MB it might not work at all as im told the tranny and its components need to be programmed/mated to my car.
is it possible for an independant mechanic to do this??
Any advice is appreciated
thank u

 

Does your car have the 5 speed? If so the conductor plate is really not that expensive way cheaper than a transmission job. Also gives you the chance to change the fluid out which will help the transmission to last for a long time. Get the car to a good shop that knows mb transmissions for a proper diagnosis.

 

I have an 05 so i believe my tranny is the 722.9 (7 speed).
The conductor plate is 631.35 + 59.95 core charge plus tax.
the valve body is $2060.20 +$197.80 core charge plus tax..
together including tax it's $3332.37
The labour is 4 hours (around $700?)
So together, im about to face a $4000 bill unless someone can come up with another idea... (help!)
So I can get a tranny for $1400 but keep being told because the tranny has to be mated to my car, only MB can do it. Is this true? Is there no way for another mechanic to do it? Its just software, and a matter of programming is it not?

 

The transmission requires a Star to be suitably coded to the car. Some Indy's have Stars. Try & find one.

 

Just got the car back it drives like new and it didnt have to be fixed at the dealer.
got a new valve body and conductor plate put in and programmed, including new transmission fluid (from mb) for $2000.

 

I have a 2006 W203 C280, after cleaning out the harness and resetting all faults an indy ran a diagnostic and he found a faulty speed sensor and said I'm better off going to a dealer to get it sorted as he doesn't touch the 722.9 tranny. Took it to a dealer, the problem could not be replicated until this morning. SA called me with a quote of $4000 USD or R32000 (South African). I will be collecting the car later today and will post the reading. Does anybody know of a good Indy in Johannesburg that could tackle this job where I wouldn't be forced to sell a kidney.

 

My car just went into limp mode and it was diagnosed and found to have y3/8y5 faulty....I understand this is a sensor called the brake clutch solenoid valve. My question is do I need to change the valve body and the conductor plate or either of the two. Help needed plsssss

 

 

Hi Glyn and Everyone
It appears you have alot of experience in Mercedes Tranny.
My 2008 W211 gets stuck in maybe 2nd or 3rd gear, it shifts really rough before this happens.
When it gets stuck, i will have to turn off the car for about 5 seconds before restarting. Quite frustrating though.
I scanned the car and got P2767 error code and also the Y3/8n2, suggesting that there are no signals from the (VGS) input speed sensors.
My major challenge is this. i suspect the culprits - The input speed sensors and the Conductor plate.
I use a 5 Speed Tranny 722.6, i cant seem to find input speed sensors for this 5G, It appears all sellers stock 7G only, for input sensors.
I am thinking, does the Conductor plate for 722.6 have the input speed sensors built with it? does the 722.6 have seperate input speed sensors? when these issues occur in 5G, is it usually the conductor plate and (or) speed sensors?
Can you help me with some clarity on these questions i have please
Thanks