As the title says our 06 ML350 is stuck!
Won't go forward or back.
Starts and runs but won't shift out of Park.
It has done this before, sometimes not wanting to go into to Park, and having to
pull the key to get it to locked. Other time not wanting to to D or R but then always mysteriously fixing itself. Either after sitting for while or
taking the key out and restarting.
There's also the issue of water in the chassis which I have not been able to determine where the heck the water is or how to get at it.
Not sure how much that has effected things.

I checked it with Carsoft today and actually manage to get a few clues and also
discovered it has to ability to do live data on shifter. Nice!

Only "Current" error is " Button P on the Direct Select Gear selector switch is defective"
Interestingly using the live data feature Button "P" is the only thing that registers.
If I push P it shows up, but nothing going to D or R.
Also a stored error which references module "A80" which from reading is the ISM a module
not longer even sold by Mercedes? Yikes! And it appears it need to be programmed with SDS in order to function if swapped.
But as I said STORED not current.




I've read a few articles about this issue either being related to the switch, or the ISM.
God help me if it's the ISM.
Someone else made a reference to the back up battery.
But in the end had the ISM replaced.

The car is stuck in the driveway! Can anyone offer some idea of things i can try on my own?
Back up battery was replaced maybe a 1 to 1.5 years along with the main battery.
I'm also suddenly having a battery drain issue, which may or may not be related. Could
just be one of those pesky seat modules. So the battery has been disconnected to charge it.
I'm thinking I'll pull the backup battery to clear any stored settings. Will that do anything?

The big main issue is how do I get this thing moving again?

 

Well looks like viewership is down in the 164 forum sadly.
Like Phil Collins says "No reply at all".
So guess what. I FIXED IT! FOR FREE!
So using my iCarsoft MBII scanner.
I really have not had a high opinion of this device in the past
as when you are in 'Benz' mode and you want to read engine codes it almost always says
the code is unknown and you ended up going into OBDII mode to say determine
a misfire location for instance.
WELL I was surprised to see that while it sux in that regard, it is able to communicate with all the
CANBUS connected modules in the car. Wow. I mean it tells you if you pushing a button or if the turn signal lights are working
without getting out of the vehicle. I did do an update on it not too long ago so maybe that's part of it too.
So I went through every module in the car. ISM kept saying the switch module was DEFECTIVE and in many other places as well.
I finally arrived at the "SCM" Steering Column Module and went through that looking at everything. Same stored AND Current errors.
Which BTW I tried to clear this error from the ISM and it came right back! So I'm thinking it needs new switch right?
WRONG! I cleared the errors from the SCM and BAMM! It was FIXED!
I'm surprised because for one thing I disconnected both batteries to try to clear whatever might have been hanging it up
but the modules still remember the errors! I mean WTF? So I guess they have EPROMM memory or whatever.

OK still need to determine bigger issue of why this happened, but now I know it's not the switch or worse the ISM which can only done by a dealer for some
thousands of dollars.
There is water trapped in the frame of the car I have not been able to get to.
Well tomorrow I'm tearing the whole damn car apart and get that water out of there come hell or high water.
Also I think I'll put come silicone sealant around the tail lights as I suspect that's where it's leaking from.
I think my problems have been due to corrupted CANBUS messages from water intrusion.
Now also I need to figure how to keep water from getting in.
Already checked the vents etc and they seem ok. Meaning front by the windshield and also sunroof etc.
All flowing just fine. Well, so that begs the question, where is it getting in?

Well I've got my marching orders, tomorrow is another day.
Running and driving again! Praise the lard! Turns out that POS iCarsoft Scanner really saved the day!
I would've needed a much more expensive unit ie SDS to clear an error like that from the
SCM. Who even knew there WAS a Steering control module. Geez.
Spoke to my buddy Mercedes mechanic today too, he didn't suggest this at all.
But apparently new benz's have up to SEVENTY yes 70 modules on 2 different buses (a newer one that uses only one wire?)
and any one of them can drag the voltage down such as 5v on CANBUS and kill communication with EVERY module on the buss.
Wow. Who knew? Images don't show the code cleared but it NOT come back. Says NO DTC's.

 

Update stuck again

 

Ok got fixed last Monday. I replaced the gear lever switch on the steering column.
Amazingly iCarsoft was right. The switch was defective.
Almost hosed the clock spring...yikes. Be careful if you do this, pulling the pieces apart in the column is tricky.
In case someone sees this post at some point, I have a post from years past (seach!) on how to take this apart
with all the WIS docs, though the pictures could be a lot better.
Take it slow.