aka.ferrari

Hi Guys, My W639 Vitto automatic will not change gears, when in Drive. The car isn't in limp mode, as I can drive at over 3000 rpm. Van can't be moved out of Drive using Tiptronic either.

My mechanics code reader couldn't pull any codes from the tranny. Not yet ready to go to MB for STAR

Any help much appreciated.

marc hanna

Which transmission does that have? One of the 5-speed 722's?

if so, probably requires a new electrical connector and conductor plate for the tranny. About $150 in parts. Some sometimes they need a couple springs replaced in the valve body too.

It's a relatively simple fix, but the dealer usually tells you you need an entire new transmission.

aka.ferrari

Yeah, it is 722. Thanks for that, I'll get into it and report back.

Also when I picked the van up I was able to get it to shift occasionally, but since the tranny service I haven't been be able to get it to change gears again.

Cheers guys.

marc hanna

I've had a few MS's with this tranny and it's always the same problem. After you replace the connector and the conductor plate you will have to get the transmission codes cleared which cannot be done with a regular OBD2 reader. You will need it done with either a Star Diagnostic or a high-end ODB2. Then it will be back to normal.

aka.ferrari

Just pulled out the conductor plate, noticed that there are no covers over the solenoids, as in picture. would this cause issues?
When my mechanics Snap On code reader was connected it was reading the transmission, but there wasn't any codes?
So what needs to be cleared? Is there a tranny reset or something?

marc hanna

They don't all have the covers over the solenoids. So I wouldn't worry about that. Did you notice if there was any oil leaking around the electrical plug on the outside, or if there was any oil in the plug itself. The O-rings around the plugs always start to leak at some point. If there are no transmission codes, just replaces the plug (usually about $10) and put it all back together (while you have it off, it is worth while replacing the conductor plate because it's usually only about $120). You can also test each of the solenoids and make sure they're working and check for any broken springs in the valve body. If there are no codes, then you don't have to clear anything. If you get it all back together and the problem persists, then it's likely a fault in your shifter assembly - there's a computer board in there too that sometimes gets gunk on it (usually from spilled coffee and soft drinks) then craps out. This almost always requires replacement of the shifter assembly. Best to look for a used one in this case, because new ones are big$$$.

aka.ferrari

replaced the plug, checked the springs, tested solenoids. are these the right test values?

modulating pressure solenoid. 5 ohms

1-2/4-5 shift pressure solenoid. 5.4 ohms

3-4 shift solenoid 3.9 ohms

2-3 shift solenoid 4.1 ohms

tcc solenoid 3.1 ohms

marc hanna

I'm not sure what the resistance is suppose to be on them, by testing them I meant applying voltage to see if they actuate. I've never needed to test mine, so I don't know the proper applied voltage either - I'm not sure if it is stepped down or up, or 12v. I did see a youtube video once where a guy did a tutorial on testing the the solenoids - a quick search should be able to locate it.

When you checked for broken springs did you look for small pieces that might still be stuck in there? The oil residue is enough to hold them in there even if you tip it up and shake it. Not to mention any metal residue that may have gotten in there, because that stuff is like glue.

aka.ferrari

so I've found out off of the last owner that the conductor plate was change a year ago so i rang the shop that worked on the van before were they told me that when it had its last problem that the speed sensor code was lodge and the van when into limp mode unlike my current symptoms so i don't think that it would be the conductor plate
so on to the next thing the electronic shift module
it does not appear to have anything spilled on it but is very dusty would this cause the transmission to stay in one gear and the tiptronic not to work also
and would it lodge a code if this was the error as i do not have any codes coming up
i have check the valve body for broken springs but they were all fine
i have some photos of the shift assembly what part is normally the defective part and what is its name as I'm having trouble finding any info online so i think i must be calling it the wrong thing is it electronic shift module any help would be much appreciated thanks

aka.ferrari

marc hanna

It's usually the printed circuit board. Some people report seeing burn marks on it, others don't see anything. I don't know how or if you can actually test it. Everyone I've heard of just replace it, usually with a used one from eBay or a scrap yard.

aka.ferrari

In the end the Vito had stored a hard code and needed to be cleared on a STAR.
Thanks for all the help.

marc hanna

What was the code?

aka.ferrari

My mechanic didnt give me exact codes but there was 15 errors in total. I'm guessing they were a mix of old and new. He cleared them all and it's has been driving great since.