2005 G55 722.6 Transmission

[Chuckles]

I replaced the conductor plate in the transmission. On the valve body there is a metal strap with a pin that fits in the slot of a shift mechanism up inside the trans housing. Also in the valve body there is a small white plastic plunger that slides in and out of the valve body. This plastic plunger has a slot molded in it. I do not see up inside the trans housing a pin or some other feature that will move this plunger in and out. I must be missing something. Can anyone help me out on how to position the plunger when installing the valve body/conductor plate assembly back up in the tranny?

Also it seems someone earlier worked on this transmission and failed to put back on the two plastic covers that fit over the solenoids. I can order the long cover but the short cover is not available from Mercedes in the USA. Anyone have any thoughts where I can purchase the cover.
Thank you
Chuckles

 

[alexanderfoti]

The plunger is in the valve body housing, and lines up with the PIN that sticks of the shift quadrant:



as long as the car is in park, all you need to do is pull the white plunger out so it lines up, then seat the valve body and bolt it up.

 

[alexanderfoti]

The covers were dropped from 04 ish onwards, so yours probably never had them, and they are not needed.

 

[Chuckles]

Thank you very much for your quick reply. I will take another look. Maybe I should put on my reading glasses this time!
Also I have seen several videos of applying 12 volts to the solenoids to very they are active. Have you done this? Do you recommend? Pros/Cons?
Thank you

 

[alexanderfoti]

You can do, but I wouldn't do it for the sake of doing it.... if they are not working the car usually will not drive at all, or the gearbox will go into limp mode as soon as it uses a solenoid that is faulty. The TCU will never apply 12V to them, they are usually always pulsed in some way.

 

[Chuckles]

You can do, but I wouldn't do it for the sake of doing it.... if they are not working the car usually will not drive at all, or the gearbox will go into limp mode as soon as it uses a solenoid that is faulty. The TCU will never apply 12V to them, they are usually always pulsed in some way.

The car presently will not shift out of first gear. I checked the fluid level. Pulled the 13 pin connector. Looked pretty crappy. Decided to replace the conductor plate, connector, etc. will button it this weekend and test it out. Hopefully it will shift correctly. Thanks for your help.
Chuckles

 

[alexanderfoti]

Are you sure its not 3rd?

When you put the car into gear, does it go in with a thud?

Have you read the codes from the car at all?

 

[Chuckles]

Are you sure its not 3rd?

When you put the car into gear, does it go in with a thud?

Have you read the codes from the car at all?

Car eases into gear with no thud or jerking motion. It is in first gear. Get up to 40 mph and the rpms are getting up there. Scan tool reads Code P0743. Problem with TCC electrical circuit. The TCC solenoid checks out at 4.0 Ohms.
cannot find where the TCM circuit board is located on the G55. Most are in the engine bay. The G55 has so many areas where electronics are secreted around the body. The 722.6 tranny wire harness are famous for the tranny fluid wicking it’s way up the wire and into the circuit board. Searched the internet for TCM location, but cannot find specific info for the G55.

 

[alexanderfoti]

Assuming the code is valid and accurate, then you should change the Torque converter lockup solenoid. They do cause issues, but usually with harsh TC engagement. Can't say I have seen this before.

You could have a tcu issue. It's in the center console:

 

[Chuckles]

Assuming the code is valid and accurate, then you should change the Torque converter lockup solenoid. They do cause issues, but usually with harsh TC engagement. Can't say I have seen this before.

You could have a tcu issue. It's in the center console:
View attachment 66464

Thank you very much. Will check the TCU as you pointed out. The actual solenoid in the tranny, you think it may possibly be suspect even though it meets its OHM spec.?

 

[alexanderfoti]

Thank you very much. Will check the TCU as you pointed out. The actual solenoid in the tranny, you think it may possibly be suspect even though it meets its OHM spec.?

Yes, they often give problems when warm etc. Even when they are ok, they give jerky TC engagement when testing. You can always leave it for next time.

 

[Chuckles]

Yes, they often give problems when warm etc. Even when they are ok, they give jerky TC engagement when testing. You can always leave it for next time.

By chance would you know of a link that instructs how to remove the center console of a 2005 G55? You mentioned the wicking effect of the electrical cable that connects the tranny 13 pin to the TCM.
Thank you alexanderfoti