imcc

I need help here... So I have been having a trans issue on my 2004 s600.
Trans showed Code P0730, Basically no forward or reverse gears. Code showed posibilities, according to star Diagnostics, of:

• Oil filter not assembled / Assemble oil filter
• Wiring harness damaged, short-circuit, chafing mark / Check wiring harness to ground.
• Shift pressure control solenoid valve (Y3/6y2) blocked (foreign matter) / Replace solenoid valve.
• Control, shift or command valve blocked (foreign matter) / Check slide valve for end position and ease of movement, free off if necessary.

• The spring in the control spool pressure regulating valve may be broken / Replace spring (part no.140 993 58 01).

Tested the Solenoids and Y3/6y2 and Y3/6Y1 were not firing on the solenoid test through star diag.

Replaced the complete valve body assembly Factory Re-manufactured Unit from Benz, put it all back together and the trans shifted perfectly and flawlessly For approximentally 60 miles! Ready to take it on a trip and it goes out! Back to Exactly what it originally was doing... Same Code Too!!!

Assuming the Re-Man Valve Body from MB Went bad I sent the Car to the Dealer for Parts Warranty Diagnosis....

Well lets just say ofcourse they state it needs a whole transmission and thats the problem, not the re-man valvebody... I am ok with this but I asked how a simple valvebody could fix a shot transmission for 60 miles and tested hard for those miles too. I have had many cars with slipping transmissions and replacing a valvebody will never fix a slipping transmission unless the valvebody is the cause...

I would love to hear some input on this.

Thank you,

Dirk

Ausmbtech

Firstly, have a look at the transmission control unit to see if there's oil in it.

Is the oil level correct when the transmission is hot?

Did the fault code trip when in a particular gear/engine load?
What does it do if the fault is cleared? how long till it comes back?

Also check the length of the shift lever, maybe it's between gear positions

imcc

Code comes back once its cleared after it slips in gear again.

Dealer swapped the TCU From another car and it still did it but it did have some oil in it.

Trans fluid was correct when hot and cold.

Fault code trips when its placed in forward or reverse and attempt to accelerate.

Shift lever is in the correct postition also...

Could the oil in the tcu have shorted the new solenoids out in the new valvebody?

Ausmbtech

When the TCU is swaped from another car it needs to be programmed for the correct diff ratio otherwise it'll go into limp mode also.

Seeing you've already fitted a new valvebody and the fault persistsit sounds like you do have a larger issue with the transmission, maybe low oil pressure or internal slippage. Probably best to get it overhauled or an exchange unit. An exchange unit is usually better because it has a fixed cost, a rebuild costs depending on what's broken/damaged.

Only other thing, when you changed the valvebody was there much debris in the pan or on the magnet?

imcc

I agree however the new valvebody fixed the initial trans problem for 60 miles and the trans worked flawlessly, no shifting issues, no slippage etc... That is the strange part to me.

There was some debris in the trans pan but nothing extreme.

How difficult is it to change the pump on the trans? I am already $1,400 into this trans to spend an additional $4000 for a factory remanufactured unit. Thanks!

C32AMG/02

Check the TCM Transmission harness on passenger side front of the transmission for Fluid contamination, fluid on the pins will short the TCM. When a valve body is replaced with MB new or rebuild, the TCM should be coded (soft wear) to the match any updates in the NEW valve body. Have you checked the TCM for Fluid contamination again

imcc

I did check that again and it was dry as can be. I replaced the orings for it when I did the valvebody just to make sure everything was ok.

I also went through star diagnostics and no coding of the tcu was required either after replacing the valvebody, unusual I thought but that was it.

Ausmbtech

So if you got in a drove it right now it would throw a code before it reach's 2nd gear or does it need to perform a shift to get it to fault? Is there a difference if you use W or C mode instead?

I'm trying to determine if there is slippage in gear or during a shift to determine if there is a broad problem (low oil pressure) or a fault with a specific clutch pack. It's very difficult without driving the car myself.

To change the oil pump you need to remove the transmission and disassemble it, not a quick fix. Also they don't cause much trouble and the oil pressure is regulated in the valvebody.

The weird part is that the fault code is a combination electrical/mechanical code instead of the usual mechanical slip code.

Is there any additional info you can give? It still looks like the box will have to come out, now you're just trying to determine the fault

C32AMG/02

Can you retrieve all shift time and fill Adaptation data, if so post them

imcc

Unfortunately at this time the car will not reach 2nd gear, it will occasionally begin to go then start slipping. There is no difference between W and C mode either. Both react the same way.

When it happened I was just driving and noticed one weird shift, 5 seconds later nothing but slippage and free revs like I put it in neutral.

At this point slippage is all I have. No forward or reverse gears. It feels like it wants to engage but will not either by pressure problem or otherwise. MB is telling me the trans is shot and thats why it will not engage but it was doing the same before the valvebody and it seemed to have fixed that problem.

Also I noticed doing a trans solenoid check that it fires all solenoids at once during its test and then asks if the test was good... On the old valvebody it was only firing 2 of the 4 main solenoids but the only way I could tell is by running the test with my hands on the solenoid to check for activation. That is why I replaced the valvebody. Should I make MB do the same while I am there? That seems to me to be the only way to actually tell if the solenoids are working properly. Right?

Thanks as always for all the help!

imcc

I will try to retrieve the data an post that also for the shift information.

C32AMG/02

At this point as a Quick test, I would over fill the transmission by adding two extra pints; this will tell if we have a filter fluid problem, crack in the filter, leaking 0-ring, lose filter or low fluid condition. Those shallow pans don’t hold much fluid. Another thought, did you torque the VB bolts down,to 100 inch pounds, if not a valve will not move.

2004 and later 722.6 transmissions didn’t have the early production problems, as in leaking sealing rings, sprag slippage, K2 drum output shaft pilot bushing failure. Valve body failure, and since there are no working pressure test ports, the only other method to verify internal fluid fill pressure, is thru analyzing adaptation data. do you still have the same codes, did you reset the adaptive data. With the same drivability condition, I don’t think we have a solenoid problem. with slippage we a fluild or pressure problem.