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I did a bit of maintenance on my 01 s600 when I swapped out my abc pump so valve cover/intake gaskets spark plugs, cleaned injectors throttle body etc. I drove the car as if it was new for about 5-600kms. Last couple days I'm noticing a few issues...
-im noticing the transmission isn't shifting properly. on low speeds there is a bit of a jump when I ease up on the throttle and its revving higher than it should so gas/mileage is twice as bad
-on highway its revving a bit higher too I'm not sure if its going it the overdrive
-when I park and shift into park it revs upto 2500
im not sure why these are happening whether its a throttle position sensor/transmission fluid or anything else that might cause these issues.
No I mean if it’s wet at the tcu . When the connector leaks fluid travels upward via wicking effect up the wiring and gets into tcu in the engine compartment
No I mean if it’s wet at the tcu . When the connector leaks fluid travels upward via wicking effect up the wiring and gets into tcu in the engine compartment
Just researched what you meant. Thanks for the heads up I'll jack it up tomorrow and start check that first. Seems like that if thats the issue that connector has to be changed and at the same time gasket and filter I guess.
First look at the TCU in the right front SAM. If the harness is wet, remove the TCU unit, open it, and if there is oil in it use brake cleaner (a lot) to get every spec of oil out of it and let it dry properly. Then look at the connector on the transmission.
ok I did a bit more research and the dealer has the parts in stock so thats the good news. I saw a lot of people saying valvoline max life is actually better atf than dealer. What do you guys think? also since I'll be just replacing 4qt thats on the oil pan would it be a terrible idea to mix the fluid types? when I called about the parts I also asked about the conductor plate and they said it has to be coded at the dealer. They said if I did the work I'd have to tow it there and bring the old conductor plate so they could reprogram it. This made no sense to me because none of the DIY videos online mention it. Where is the tcu in the engine bay?
The TCU (Transmission Control Unit) is in the black plastic box in the engine compartment, near the right corner of the windscreen/windshield and the hood hinge.( Left/right are always defined as if you were sitting in the driver's seat.)
Unlatch and remove the lid. Look closely at the small wire harnesses coming in and running down into the box. If you find traces of oil on a harness, that is probably the TCU harness. Gently work the end of the wire harness up out of the box - the TCU is a small plastic box, about the size of an old-fashioned cigarette case.
Carefully open the case by releasing the little plastic clips. Use a spray can of brake and parts cleaner to completely remove all traces of ATF in the box and the wire harness. Let dry thoroughly, reassemble and reinstall.
My preference for ATF is Shell ATF 134. Sometimes hard to find, usually available at a Shell Distributor, relatively inexpensive, carries MB approval.
Don’t mix Maxlife with oem
fluid . Just get oem fluid from the dealer or get atf134 from a cheaper source , usually you’ll need to go online to find it cheap .
The 7 speed transmission conductor plate needs coding , used in 2004-2006 v8 cars . All the v12 used 5 speed 722.6 automatic and the conductor plate needs no coding
Don’t mix Maxlife with oem
fluid . Just get oem fluid from the dealer or get atf134 from a cheaper source , usually you’ll need to go online to find it cheap .
The 7 speed transmission conductor plate needs coding , used in 2004-2006 v8 cars . All the v12 used 5 speed 722.6 automatic and the conductor plate needs no coding
Ya Ive been looking into a bunch of posts about mixing fluids and seems like shell134 is the approved fluid. I was questioning mixing 4-5qt of that with the original fluid would be fine. I jacked up the car even. I'll drop the pan tomorrow morning and check the conductor plate but Im not sure if changing is is necessary. I'll grab the filter/gasket/lockpin/new screws from dealer and grab some of the shell...I'll check the connector in engine bay as well. If anyone feels I'm missing something I'd appreciate a heads up.
The "connector" is on the transmission, where the wire harness runs up to the TCU. It leaks internally a very small amount, but that is enough that ATF wicks up the wire harness and gets into the TCU. http://www.mercedesmedic.com/722-6-t...sion-plug-diy/
Update so far...
I read a ton of posts about fluid choice, availability etc and long story short I got 6L for 14.50$CAD per liter from dealer after a loyalty discount of 15%....shell is extremely hard to find and another store was going to bring Fusch for basically the same price
I got the bolts, washer, lock pin and dipstick today. Mb connector and febi gasket/filter kit come in the morning
I drained and dropped the pan. Good news is its very very clean and no gunk at all on the bottom of the pan. There was no magnet like I thought there would be so I'll see if I can grab one before I put it back on.
I couldn't figure out how to slide out the tcu in the engine bay. I left it alone til I figure out how to take it out properly without breaking something in there but I noticed no oil on the outside wires coming in. I'll still take it out and check tomorrow when I take the connector off the transmission.
The conductor plate doesn't need replacement unless there wear I guess so I still want to drop the valve body and take a look while pan is dropped.
Last edited by Batu Han; 09-27-2018 at 07:51 PM.
Reason: update
So I got all the parts but I'm contemplating if conductor plate needs replacement. I had no codes. and less than 4 qts came out. I goofed and didn't warm up the car before I drained but still seems like it was low so I'm hoping that was the problem that I noticed with the weird shifting and revving I was getting.
Everything is very straightforward so far and fluid was clear. The plug is a bit wet but wasn't excessive by any means. I got electrical cleaner and sprayed both ends but I wanted to take out and inspect the conductor plate. Can I get away with not replacing this? is it possible to inspect the plate itself to see if its good or since I had no codes etc its still good
I finished the transmission service. the idle problem is still very much there. Any ideas what else could cause this? I have no codes. Drives pretty well but rpm floats between 900-1500 when I'm off at park. driving on low speeds theres still a bit of throttle play. And when I'm shifting between gears, on neutral, and when I park after driving it jumps to 2500. What could cause this?
doesn't sound like a transmissiion problem to me - more an intake air leak or a throttle (gas pedal) control.
What are you using as a code reader?
ok my bad let me rephrase that...I don't have any warnings on dash, I didn't scan with star or obd2 etc
Originally Posted by tusabes
You still didn’t pull the tcu out did you ?
no I didn't want to snap it because it wasn't sliding out easily...I have a really bad habit/sht luck when it comes to clips etc, I end up snapping them and sometimes cause more damage but the wires on the connector were all dry. The connector in transmission was also barely wet...
09-22-2018, 01:52 PM
