[722.9] Valve Autopsy car is not moving

[Oldspanners]

Sorry I don't catch you.

On w209 esm no needs to be coded.
I will remove one more time the valve body ! I can do it bindfolded !

Have you access to wiring diagrams and check the connections between the ESM and TCU.

 

[desmofab]

Yep already checked

And it works before removing the valve body.


I have one "crazy" hypothesis, I had some magnets fragments on my desk and found one on the Y3/8S1 spare component.

I am wondering if it can perturb the electrical signal to the TCU...
Now I can move my car so I will be able to do some mechanics inside.

I will keep you in touch !

 

[desmofab]

Here we are again !




My motorbikes are jealous....

 

[Oldspanners]

Here we are again !


View attachment 53931

My motorbikes are jealous....

View attachment 53933

The auge from Brico marche are perfect for collecting the oil I've two, one to drain and the second to collect the drips.
Good luck.

 

[desmofab]

And the result is ... no progress !

Or not enough, now Target Gear can change to neutral in case of the switch is set to R or D, put the car stay in place...
Without the TCM plug is still ok...

I tested all the component and everything is okay. No error code ... Tomorow, I will try to make a gearbox adaptation, I have cleared every values.

 

[Oldspanners]

And the result is ... no progress !

Or not enough, now Target Gear can change to neutral in case of the switch is set to R or D, put the car stay in place...
Without the TCM plug is still ok...

I tested all the component and everything is okay. No error code ... Tomorow, I will try to make a gearbox adaptation, I have cleared every values.

Have a look at this video it may be of interest and the last comment about a 2005 SLK.

 

[desmofab]

Yes but unfortunately I didn't have error code :/

 

[desmofab]

But now I can say that there no mechanical issue but a piece of the puzzle is still missing

 

[desmofab]

Reflexions of the day

I could not explain why the car was able to run before the dissassembly but I was in "limp mode" so electrical function was disabled.
For the time being I didn't have any error and SCN coding seems to be ok BUT I bought the couple TCM/Valve body in Russia and I think they made an hardware tweak to bypass SCN protection, I don't if it's possible.
Because, I didn't made the "online" coding the TCM has not been update.

I Will try to do an offline firmware upgrade but I don't know if it still possible with Xentry 2019. In any case it doesn't matter I already found an online accout



Emergency function/Limp-home mode:
There are a variety of failsafe modes; if a solenoid is defective the gear affected is blocked (example solenoid Y3/8y7-B3 clutch is defective: no 1st, 7th or Reverse in “S” mode) If hydraulic fault prevents a gear from engaging then the previous gear will be applied. If the computer defaults while driving, all solenoids will be turned off. Solenoids that are normally open will allow full pressure to selected clutches and the transmission will be in 6th gear. After shifting to “P” oil pressure from K2 solenoid is redirected to B2/BR solenoid via emergency operation valves and the transmission will now achieve 2nd in “D” and Reverse

 

[star]

So as I understand, the gearbox was in limp mode, you took the valve body apart and now it doesn’t drive?? If that’s the case, then it’s something you have done in the valve body. Correct me if il wrong as I Don’t read long posts.

 

[desmofab]

It was my first idea but without TCM plugged in, the car can move

 

[star]

So it did move before you took it apart?

 

[desmofab]

A quick summuary :
- Orignal VGS1 TCU burnt
- Found TCM/valve body VGS2
- Fit the new TCM, car is moving but limp mode due to solenoid default
- One broken spring and one solenoid changed
- Once fitted, no error codes from TCM but car is not moving. Without the TCM the car is in limp mode but is moving

 

[star]

Fit original valve body with new/shand tcu?

 

[desmofab]

Good question I have not try. But VGS1 valve body should not be compatible with a VGS2 TCM

But for my side, this is not a mechanical issue because without the TCM the car can move.
So, it should be an electrical issue however I don't have any error code from MB Star, I think, the issue comes from the firmware.

Due to I didn't do an Online coding the TCM could not be updated with the right version for my car.

 

[star]

Without a fault code, you have been guessing. Put all the original parts in and read the faults.

 

[desmofab]

I can't the TCU is definitely dead ! The orignal default code was U0101.

You don't think that my supposition could be right ?

 

[desmofab]

Hello all,

Offline programming was done but no progress.

Or almost ! I think I have find the root cause, it should be scn coding I got an 513 error.

Now any help is welcome I have to reste scn but i do not have abrites it seems that it can be done via xentry and Dev mod. After that I will do a online coding.

Keep you in touch

As an information, I did that via DAS :

But I don't know if it's engouh to erase old SCN...

 

[Karwan]

Hello I know it's almost a year passed since last update on your issue, as Iam almost in the same situation like yours I was wondering what was the outcome of your issue.
The garage opened my 722.9 conductor plate, clean it and changed one Blue cap solenoid (the one operates the torque converter). Now the car only moves in Reverse not in Drive.

 

[Wighty]

Hello I know it's almost a year passed since last update on your issue, as Iam almost in the same situation like yours I was wondering what was the outcome of your issue.
The garage opened my 722.9 conductor plate, clean it and changed one Blue cap solenoid (the one operates the torque converter). Now the car only moves in Reverse not in Drive.

When you say garage , do you mean a Mercedes Specialist ?