Much like the Chevy Nova introduced in Mexico, my transmission is NO GO!

2005 Limited Edition Roadster Automatic Transmission

OK Here is what I did:
Got a new filter and O-rings for the electrical connector. Dumped the fluid, changed the filter. Replaced the O-rings on the electrical connector. Put it all back, flushed the fluid using the out 3 in 3 method. While I was dumping fluid out, I would shift the transmission through the different modes, park, reverse, neutral, drive, and then back through the modes back to park. I got it mostly filled and found out I did not have enough new fluid. I went to my local Mercedes dealer and got three quarts. OUCH. It was expensive. Put in two, check the level. It seemed to be showing ok.

I test drove it. Worked GREAT! Much smother shifts. Parked the car. Did some more clean out for evening ride. I got it ready, put it in drive drove about 10 feet paused, to get the right song on the stereo and then the transmission quit. No noise just hit the gas and no power. I can put it in park and the car stops, but it acts like neutral in reverse and drive.

I consulted the manual for troubleshooting. The only thing I can do is check the fluid level. it seems to be full now and showing about 50 mm at 100 F.

I have no idea on what to do next.

 

I would check that you have the electrical connecter properly plugged in.

 

"Replaced the gaskets on the electrical connector" ??
Are you talking about the two o-rings? Did you use a new plastic plug or the old plastic plug with new o-rings. The new plugs from Mercedes will not work on our cars. You must use the original plug with new o-rings. If it wasn't leaking you should have left it alone.

 

Sorry I should have said O-Rings instead of gaskets. I used the old connector. And it was leaking hence I really wanted those replaced. So far no drips under the car.

 

Edited the original post for clarity. Does anybody know if transmission codes show up on ODBII can bus? Does anybody have any good substitutes for a DRBIII scan tool? I have not gone back under the car. I was just so discouraged.

 

This has not been answered! I am still not showing any codes.

OK I got the car jacked up at lunch today just to do a basic diagnosis. There is a bit of fluid leaking around the electrical connector. I will need to remove the heat shield to pull it and check the connector. I did start the car and put it in gear. Looking at the drivers wheel I can see it rotate when I give it gas. What's funny it rotates forward both in reverse and drive. Still looking for suggestions. I can replace the conductor plate that's about the only thing I can do.

 

I believe some of your issue(s) is/are you might have transmission fluid wicked up into the TCM under the console, also, the wheel rotating when in drive/reverse in the same direction, I believe is normal. Fix the leak and check the wiring up to the TCM for wicking of the transmission oil. Good luck!


.

 

Thanks! This is something I can do. I pulled the access plate for the stereo and the TCM. No issues with leakage there.

TCM and amp



Wiring and TCM

The wiring around the TCM was dry. My next tactical move will be to remove the transmission pan, and check the valve body. Make sure the shift lever is engaging correctly to the selector valve.


transmission selector valve


After that will be replacing the conductor plate.

 

You should not have a leak at the electric plug after putting on the new o-rings. Make's me think you messed something up when inserting the plug after replacing the o-rings. The plug connects to the conductor plate, so if you get that far inspect the connection. You might find your problem.
There is much discussion here on scan tools for our cars. Many can be had for under $200 that will give you the transmission codes. I have a Foxwell, but be advised you have to go thru a download to get the proper programing ( I used the Mercedes download) It works quite good on both my Crossfires and our Mercedes CLK.

 

Check your connections!

 

The connections have been checked. Thank you @zip439 and @oledoc2u for your suggestions. While I had leakage around the electrical connector, I think the O ring around the connector needed replacement. So I think I have root caused the issue. I think the plastic part to the selector valve is broken.

I found this in the bottom of the transmission pan. I have cleaned it up and placed the plastic part back where I found it:

broken plastic bit that should not be there


Look in the circle

The beige plastic bit is the selector valve. The selector valve is what tells the system to activate.


Selector Valve chooses P, R, N, and D for Drive

Now I need to pull the electrohydraulic unit and find all the broken bits. See I can find a replacement part. This will prevent me from going to the fall rally.

 

.


Good catch on the broken part. Can the linkage part be separately parted (if not new, maybe an assembly from a recycler)? Way back @ 1980, my old Chrysler New Yorker Brougham's transmission had a nylon gear separator part (broken/ragged) in my transmission pan, during a transmission servicing at a supposed reputable transmission shop (was later explained after I almost got scammed into a new transmission it was just there for the assembly of the transmission and most either self destructed or stayed in place throughout it's life). My thanks to my friend who worked in a dealership service department who told me about it & saved me a huge amount of $ (at the time unavailable funds). That little part in your pan reminded me of that affair. Hope you can source the part you need without having to remove the transmission! Good luck!


.

 

Never heard of this happening…I have two to service very carefully

 

Well there is always a first for everything. I have a talent for finding firsts. Or the Broken Car Gods like me.

Well I have been searching, found just the linkage for about 100 on ebay. At this point, I would rather replace the entire valve body. I have seen refurb units for about 200 to 350$ Going to the dealer/Mercedes the valve body is about $1500. Does anybody have any experience buying a refurbished valve body that does not cost an arm and a leg?

 

I would just do the linkage at this point. You may open up another can of worms…

 

I read your other post. As I said, I have a transmission that is good that you can just have, but also, I think I have that shift select valve from another trans. You can have it, also. They also will be readily available on Ebay, and not very hard to change. You will need to pull the valve body down to get enough room to pull it out, but that's all it does. It pulls straight out, and a replacement goes straight in. Second, it may seem obvious, but you were checking fluid level with the engine running, on level ground in park or neutral, correct? I have to ask. People do get that wrong.

 

I will take that transmission! Thank You I live in Columbia SC. I will be most happy to put you up for the night too on your long journey! I will pull the valve body completely out. I want to make sure I can find the rest of the plastic.

I did all the checking of the fluid in park with the car running. I am not sure if that's correct or not.

 

The good part about these transmissions is that any junk just falls to the bottom of the pan. Light stuff might wind up in the filter, but that's it. With the rotating internals inside their own chamber, there's virtually no risk of a piece of plastic making it up into there. As I said in the PM to you, you are welcome to the trans. We live in the Florida panhandle, and will come up through Atlanta., There is a route we could take to go through Greenville, SC, but that is as close to Columbia as we will get on this trip. Let me confirm I have a spare shift valve. If I do, pay for the shipping, and it is yours. It will take at most 2 hours from where you sit now to getting that car ready fore the Rally. I think all involved would prefer to help you make it there.

 

I finally removed the valve body to see about rebuild or replacement. For some reason the selection lever broke and caused my transmission to no longer shift into gear.


The missing chip is on the right hand side

 

GOOD catch, that is quite a failure mode there. I hope you find that part, it'll get real expensive if you can't... Good luck!


.