Rudeney

No, I didn't DIY. I wish that I could have. I paid the dealer $1400 for the job. I've been having the symptoms over the last two or three years. Maybe one every two or three months, I'd get a limp mode. Turning the engine off and restarting always fixed it. Until Monday of last week.

I went to leave the office after work. I started the car and droAApped it into reverse to back out of my parking spot, and - nothing. It's like I was in neutral. I drive drive, and same thing. So I shut it off, and restarted - same thing. After five or six tries, I figured I would call for a tow, but then I decided I wanted to get my SDS computer and check it first. I needed a ride home and back so I called my Dad. I would have called the wife, but she was at the nail spa. Besides, Dad loves getting out of the house and fooling around with cars.

Anyhow, it's been hot as Hell here, so I sat with the engine and AC running while I waited. After a few minutes, I decided to try one more time, and guess what? It went right into gear and drove just fine. I called Dad and cancelled, who luckily hadn't left the house yet. So I got home around 6:00pm no problem. I had some things to take care before looking at it, so it was probably close to 9:00pm before I hooked up SDS to check it. It would not communicate with the TCU! Hmm. Tried starting it and again, and no transmission - it acted like it was in neutral. It was late, and I have the C240 as a spare car, so I just left it for the night.

The next morning, I tried again and no-go. So I drive the C240. And then I discovered it had NO A/C! WTH?!?!? The hottest week of the year with 100F temps and NO A/C!!!! Well, id probably be driving the CLK with the top down anyhow, so I just rode with the windows down. As an aside, on Wednesday, the house A/C compressor died. Really???? Luckily my uncle, a retied mechanical engineer, has his HVAC license to do work on the side so he came over Thursday and we replaced it.

I noticed that the "P" and "S" transmission mode indicators on my cluster were missing. Hmm. That and no SDS communication with the TCU had me guessing this was "catastrophic" transmission conductor plate failure. I had found an eBay listing for a guy in California that repairs 722.9 conductor plates for about $300. I assume transplants my TCU electronics into a new conductor plate, so it needs no new coding. I called him to discuss what he does. He was very vague about it and when I told him it was not talking to SDS, he said he didn't want to touch it. Also, another symptom I had was "clicking" when shifting into D or R from neutral, and also when taking off. I assumed it was the sound of the turbine speed sensors slopping around in their sockets in the warped conductor plate. He said that was not a symptom of failure he could repair. So, this made me decide to just tow it to the dealer.

Before I did that, I had something of an epiphany. I remembered that I tried many times to start and stop the engine on that Monday at work, but only after sitting and idling for ten minutes did it work. Hmm, maybe the problem is temperature related. Maybe once the transmission warms up, the conductor plate would work. Sure enough, after about ten minutes of idling, everything was up to temp the "P" and "S" indicators appeared on the cluster and I could drive. And SDS now talked to the TCU and gave me the typical turbine speed sensor errors, plus a CAN bus communication error. Oh, and i had an engine MIL illumination with a TCU CAN bus error, too. I did not clear these.

Oh, one other thing - a few days before the failure, I was on the highway using cruise control. I noticed that the "ring of fire" indicator on the cluster was a bit dim and almost "blinking" like a bad bulb. Cruise control even dropped out at one point. I thought maybe it was a cluster problem, or maybe a wheel speed sensor issue. But this also came back to mind when the conductor plate failed.

So, to wrap it up, I took to the dealer, and two days later, and $1,400 lighter, it's fixed. It was the conductor plate. I drive it today and it shifts just fine and even feels a bit sportier on shifts. Maybe due to new TCU code or maybe due to bad signals from turnbine speed sensors. There are no more clicking noises. But I still have some transmission whine at idle that the car has always had. I suspect that's the main fluid pump, which is another typical fault in these early 722.9's. The dealer did change the filter, but the invoice shows only 6 quarts of fluid, meaning they didn't drain the torque converter. i was going to mention this to them, but I forgot. Oh well, i changed it at 40K, and it has 75K now, so if I'm still driving it at 80K, I may do a full change again.

xsever

Thanks for sharing your experience Rudeney. I had the same happen with my 2003 CLK 320 back when I lived in Canada. My current 2005 CLK 320 has been bulletproof.

It's very sad how between imminent transmission problems (conductor plate, valve body, etc..) and imminent engine problems (balance shaft), the 06-07 CLKs are really not a good choice. MB suffered from this problem with the conductor plate on 03-04 models, got it fixed in 05, yet got back into it with the new 722.9 in 06-07. You'd think they would have learned a lesson or two from the 03-04 troubles.

Anyway, glad you got it sorted but at $1,400, that's pretty significant. I remember mine costing me CAD $1,300 back in 2014.

I advise anyone I meet who is looking into buying a CLK to go with an 05 model or an 08-09 model to stay away from all this unless he has proof that the conductor plate has been changed as well as the balance shaft problem addressed.

Rudeney

Your MY2003 had a 722.6, which is a different conductor plate. In that one, the plate is simply a plastic housing with electrical contacts to transmit signals to and from the TCU, which is in the passenger compartment. The 722.9 conductor plate does that, but also contains the TCU. Not only does this make the 722.9's plate more expensive, it's also a dealer-only job as it has to be SCN coded.

Also remember that the MY2005 V8's had the 722.9, so I'd add those to the "avoid" list. But then again, even with the threat of balance shaft and transmissions problems, the xx350 and xx550 cars with the 722.9 transmission are very satisfying to drive as compared with the older xx320 and xx500 cars with the 5-speed 722.6. I generally recommend that prospective buyers avoid cars in the balance shaft trouble range because of the very high cost of repairs (usually over $4K). But with the transmission, the repair is usually under $1500, which is not cheap, but amortized over time is not that bad. Also, transmission problems and balance shaft issues are not common enough to even create a blip on the "car rating" websites.

gixxerboy

how do you expect them to drain the torque converter?

Rudeney

The torque converter on my car (and most all but the very earliest 722.9 transmissions) has a drain.

kb24forlife24

I did a 722.9 service on my '05 500 recently and my torque converter did not have a drain.

Rudeney

Are you sure? Did you rotate the crank all the way around go check for it? Some people (even MBZ techs) don't realize that the torque converter housing actually rotates, so you must do that to find the drain. My understanding is that only the very early 772.9 transmissions lacked the drain, which would be the MY2004 SLK.

kb24forlife24

Yeah, me and my dad rotated it like 5 times and didn't find anything.

Rudeney

Interesting. I have not heard of a CLK without one, but I guess you could have a very early build.

Sal_Monella

Rodney, I know this is an old thread but was wondering if you can enlighten me just a bit.
Your CLK550 was a 2007 correct?
I have a 2007 S550 with weird shift issues. It sometimes revs up when it's changing gears and feels like a smart car has rear ended me at a slow speed.
It's never gone into Limp Home Mode nor has it just sat there revving and not moving. But it does the Hurka-Jerk sometimes when it shifts, oddly enough around 1500 RPM.
From what I have read the dealership won't fix or repair the Conductor Plate on a 2007 with TCM version VGS1.
According to the dealer they need to replace the valve body to allow a TCM VGS2 or 3 to be installed, then they re-marry all of the security stuff.
The cost is somewhere around $3500 IIRC.
So my question is this: Did they just reprogram your TCM or did they R&R the valve body and stick a new Conductor plate on?
TIA,
Sal

Rudeney

Hi Sal,

I had a few issues with mine. The first was due to low fluid, which happened when they pulled the engine to fix the "balance shaft" (actually, just an idler sprocket on the V8). Apparently, they neglected to check the fluid level even after disconnecting the transmission cooling lines and losing over a quart. It would "slip" when changing gears. It was really bad between 1st and 2nd where it would over-rev and then slam into 2nd. Other shifts were harsh, too. I took it in and they corrected the fluid level and also updated the TCU code and all was well, at least for that problem. In fact, the new code had it shifting very nicely in all conditions, and overcame the harsh downshift to 1st by delaying that until the car came to a full stop.

It was several years later that I started having the typical speed sensor issues. At first, I'd just get a limp mode every month or so. Eventually it was in limp mode several times a week, and then finally it got to where I could not get the transmission into gear until the fluid was well warmed. This happened in the winter, so I'd have to sit and idle for 15 minutes or so on a cold start. The dealer simply replaced the conductor plate (only), SCN coded it, and all good. Well, that is until the cracked flywheel started falling apart. That was caused by improper mating of engine and transmission during the "balance shaft" repair. It seems that sometimes dealers do more harm than good.

Now, in your case, if you aren't going into limp mode, it's probably not the speed sensors that are the issue. Have you pulled codes with a suitable scanner that can read the TCU? Also, your car being a MY2007 should have the VGS2NAG2 valve body and conductor plate as that was introduced for 2005.

Sal_Monella

Thanks Rodney, I appreciate the rapid response. We were gone off on a family camping trip at 0'dark thirty on the 19th and didn't see your response.
I've done some research and now realize that the transmission fluid level check must be performed by the dealer or a shop that knows to check the drain stand pipe.
Why they didn't make this user serviceable is beyond me.
What scan tool do you suggest?
My wife has a problem free 2013 Audi Q7 TDI Prestige. Is there a scan tool that I can use on both vehicles in the event something does go wrong with her Audi?
Any suggestions for a quality scan tool that will also allow me to clear codes?
Thanks again for your help.
Sal

Rudeney

The fluid level can be checked yourself - it's just a bit more complicated than pulling a dipstick. You have to lift the car enough to be able to get to the transmission pan drain plug AND have the PAN level. This can actually be done with a floor jack and jack stands. I've done this many times in my home garage on many MBZ models. The most interesting is the W164 where the engine and transmission are mounted in a rearward slope, so the front wheel stay on the ground, and the rear gets lifted high to get the transmission pan level. Oil is added bu pumping it into the drain plug. There are various tools to do this, like the Assenmacher pump I have, but many people just get the proper threaded tube to insert in place of the drain plug, and a cheap hand operated fluid pump, such as from Harbor Freight. The level is checked with the engine running, transmission in park,and the oil at 113F/45C. You can check that with an infrared thermometer aimed squarely at the pan. To check the level, yhou open the drain plug and observe the flow rate. If oil drains out in a strong, steady stream, then it's overfilled. Once it changes from a steady stream to a weak, sputtering stream, then it's art the proper level. Of course this means that to set or check the level, you really need to overfill it so you can watch it switch from "steady" to "stutter". Here's the WIS instructions:

http://benzbits.com/722_9/FillFluid.pdf

As for a scan tool, SDS (Star Diagnosis) is the best as it's MBZ's tool. It includes WIS and EPC and other resources. But for someone on a budget and with more limited computer skills, the Autel MD802 Maxdiag Elite seems to be a great choice, and I think ti works with many other cars - possibly the Audi.

Sal_Monella

Thanks Rodney,
That's excellent and timely info.
Next time I'm in Birmingham for a motorcycle race I'm buying the beers & steak!

Sal

Rudeney

Sounds good! I assume you go to Barber's? I've not been out there, but I hear it's great. I was invited to a track event (ironically through BMW - MBZ gives me no love these days!), but scheduling didn't work out. I always plan to go to the Honda Indy Car Race each year, and again, the scheduling is never right.

dcsimmons

A few questions with regard to a 2006 MBZ E-350 transmission.
Question 1:
I have the Autel MaxiSys Elite. Can I marry a virgin conductor plate to my car with it, or do I need to take it to a shop.

Question 2.
My car has 180,000 miles on it, but had a new valve body installed by the dealer at 90,000 miles. It worked flawless, except for a somewhat hard shift into 4, but all the rest of were smooth and perfect. Then I did an update to the software of the transmission with my Autel MaxiSys Elite, and reset things. It started doing flaky things, doesn't go into the official "limp mode", but quits shifting and throws a code: Nine times out of ten after shutting off the car, I can start off in 1st gear, and shift through to 3rd or fourth, but not beyond. One thing it does when you are first taking off in 1st gear, as you are accelerating, it feels like it is shifting into the second gear, but it doesn't actually do it, and instead continues to pick right off where it was, a short while later shifting into second. It feels like a normal shift when it actually shifts, but it is weird and something I never noticed initially.

The actual code thrown is: 0721 "The signal of the transmission output speed is implausible compared with that of the wheel rpm.

I drove the car 2000 miles from the Midwest to Arizona with it the way it is by putting the transmission into neutral going down the road, turning the car off, restarting it, and re-engaging the transmission. It would then go into the correct gear for the speed of the car and except for not shifting gears anymore.

I am suspecting resetting things is more of my issue than updating the software, but i have tried to get all the shift points re-established, but can't successfully do it now because it quits shifting and throws the code before I can get to the upper gears.

Any suggestions would be greatly appreciated.

Rudeney

I doubt Autel can code a 722.9 conductor plate since it requires SCN coding, which is encrypted data created by MBZ corporate as an anti-theft measure.

dcsimmons

I thought that was the case, but the Autel scanner does seem to do a lot. Thanks for the reply.

exhaustgases

I found information that older CLK430's don't need any programming when replacing the conductor plate. There are many youtube video's that support that.

xsever

The 430s don't have the 722.9 7-speed transmission. They have the 722.6 5-speed transmission which yes doesn't require programming.

Rudeney

The 722.6 5-speed transmission conductor plate is simple - it just houses the speed sensors and electrical connectors. The TCU is located inside the cabin, under the passenger footwell. There is a large, round 13-pin connector that plugs that connects the plate and TCU. That can sometimes leak and even wick oil into the TCU and cause issues. Replacing the conductor plate on a 722.6 is fairly inexpensive and easy - it's just some wrenching and no coding is needed. Even replacing the TCU is the easy - they can be coded for various features and adaptations, but a used, identical TCU is a direct swap with no coding needed. A brand new TCU would need simple coding..

When the 722.9 7-speed was developed, the TCU was placed inside the conductor plate. This eliminated the need for the large 13-pin connector. There is now a small 4-pin connect on the transmission that rarely leaks. The challenge, though, is if the conductor plate or one of its sensors fails, you need a much more expensive part as it contains the TCU. On top of that, the TCU for the 722.9 also required SCN coding, which is part of the anti-theft system where the VIN is encrypted into its code. This pretty much requires a visit to a dealer as they have access to that encrypted coding that gets downloaded from MBZ corporate. A used TCU cannot be used (well, there is a way, but it's not easy and is not much less expensive that having a new one coded by the dealer).

Nick Louis

My 05 CLK500 with approximately 108K miles had gone into limp mode twice over the last few weeks. It's always happens in the same situation when I'm driving home from work, never to work. What happens is I'm driving at normal highway speeds and eventually reach an area where traffic builds up. Once I slow down the car enters limp and doesn't go over 20 mph which has been fine so far because I'm driving in traffic. Once I get off the highway, turning off the car has always solved the problem. Hoping I don't need replace the conductor plate. Is there something else I should check out or get serviced before the problem gets worse???

Rudeney

It does sound like the typical conductor plate speed sensor failure, but to know for sure, you need to get codes pulled. You'll need a tool that can read beyond generic OBDII codes. SDS (MBZ's Star Diagnosis) is best, but there are others like MD802.

cbchuter

Hi Members!

I thought that I would just add a few observations having just changed the Conductor Plate on my 2011 E350 CDi 7G-Tronic.I won't recount the whole job as that's been done many times.

Firstly, I can tell you that the checkballs WILL fall out of the valve body if you tilt it too far contrary to a couple of YouTube presentations. However, this is not a disaster because the following link has a picture showing the locations of the 14 steel and 2 composite ball plus the filter screens:

https://vdocuments.mx/checkball-import-3.html

A useful site and many thanks to them for providing it.

My W212 had done 60,000 and there was enough cack in the valve body to have made it worth the effort of carefully opening it up and cleaning it.I started with a normal cleaning fluid and then sprayed with isopropanol alcohol or similar. I also used microfibre cloths for the final clean and inspection.

I had the Conductor Plate overhauled by MD Automotive Centre in Devon and I was happy with the service, especially the turnaround time. They charged me £215 including the return postage and that comes with, I think, a 5-year warranty.

Having rebuilt the valve body and plate, I did have an issue offering it back into the transmission casing. I found that I had to engage D and leave the ignition on to get the selector to move the quadrant back far enough to engage the selector shuttle. I also used very long 6mm bolts to hold the valve body up initially so that I could ensure it was pushed home evenly.

I then faced the problem of getting out the last 3-4 litres of oil from the torque converter and cooler because my TC has no plug. So after bolting up the sump and before refitting the cable bracket at the front left, I removed the bolt and pulled of the cooler RETURN pipe. This is on the right-hand side of the box. I fitted a plastic tube over the pipe and led this to a clean container marked so that I could measure 4-5 litres accurately.

Next, I made a refilling tool from a 10 litre garden sprayer. I slid a piece of 10mm copper tube to the bottom and sealed everything off so it would pump fluid upwards. I then added the same amount of fluid which I had removed from the box during dismantling (all of which I carefully kept for measuring). In my case, this was almost exactly 5 litres. I shut of the valve to prevent oil dropping back and then ran the engine, collecting 2 litres of oil from the return pipe. Then I added 2 litres from fresh and shut of again. Repeating this one more time, I now had 4 litres in the waste bottle + 5 litres originally extracted = 9 litres and I had 1 litre left in my supply tank which had started out as 10litres. I refitted the return pipe, added a final half a litre, locked off the valve and re-started the engine. I connected the computer (I use Delphi software) and watched the temperature rise. It took a long time (half-an-hour?). I also operated the gear stalk a few times. When the temperature reached 45C, I removed the adaptor and pipework from the sump and allowed oil to run out until it was a dribble. I then fitted a new sump plug and seal.

I've seen this job done on axles stands but to be honest, I wouldn't fancy it!

The transmission now runs as it should and all of the bumpy and uncertain changes have disappeared.

Hope this helps a member or two...

Nick Louis

Finally brought my 05 CLK500 110K miles into local indy shop. Turns out the conductor plate has gone bad and needs replacement. The new conductor plate was installed but be couldn't programed. After doing some research, he told me when replacing the VGS1 or VGS2 versions to VGS3, the body vale needs replacement too. To my suprize I was told the new valve body must be purchased with a conductor plate and is not sold seperate. Is this true? Luckily the conductor plate he ordered is still "virgin" and could be used for another car. Im already $1100 into this repair and worried what the final bill is. Is the new VGS3 conductor plate superior to older versions and should one expect this repair last for a while? Has anyone done this repair and know what it roughly costs with the new valve body?