PeachParts Mercedes-Benz Forum - 97 S420 Transmission Trouble

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Quote:

Originally Posted by jvmaxime (Post 2175058)

I like your idea. I think I'll try it this weekend. I have one final question. I know that it was because of the ATF on the board I was showing the code P1747. Does it 100% mean that ATF is a conductive liquid? I asked because the same fluid seats all over the conductor plate inside the gear box where all the electronics are exposed. That confuses me a whole lot.
Best regards,
Max.

That's an excellent question, and a great point.

It seems like the fluid would also short out the pins going into the connector if it were conductive.

So that implies "no", but doesn't explain how it shorts out the circuit board.

I guess it's possible that on the circuit board, the voltages are higher, and the components are in closer proximity?

Quote:

Originally Posted by jvmaxime (Post 2170298)

Hi everybody,:D
I think with all your help, I may have found my problem with this 97 722.6 gear box.
After I read your posts, I decided to investigate the problem. I went and replaced the connector at the gear box. I found alot of fluid in it and since the connector was only $8.00 at Germanparts.com, I went ahead and purchased it. After I replaced it, I still had the same problem. So I did some more investigating. I went to locate the TCM (transmission control module). It is under the hood inside a black box with a yellow sticker that said Battery in trunk. As soon as I removed the harness to the left of the module, I notice ATF at the connector. I then removed the module out of the box and laid if upside down on a white sheet of paper. I had so much ATF coming from the module I said ":P I can't believe it's not butter" I cleaned the board out with electric spray and let it dry overnight. I have some pictures for you all. In a few days I'll let you know if the problem is fixed.
Best regards,
Max

jvmaxime,

I had at least 3 ounces of fluid in the ECM box! I'm surprised there wasn't any tripped transmission codes.

I followed your lead and got the electronic cleaner and did a very extensive job on cleaning it until the cleaner was no longer pink. What a mess. Also drilled a couple of 1/8 in holes in the bottom at each end.

Thanks for your help, much appreciate. If you are ever in the area, the drinks are on me.

The fluid itself is not conductive, however as the trans wears the graphite material from the clutches can shed. graphite is conductive.

Just a thought tho

good job on drilling holes,why mercedes never tought of that?Yes some tranny fluid are conductive,and non conductive.Always carry the right fluid in case of leaks.