Richard0059

Transmission only has reverse & drive, the unlock button is not working ...

I believe it's only to release from park so it's won't work on this issue ...

Did a scan and no electronic issues ...

Do I need a new shifter?

Any ideas?

tjts1

Did you read codes from the TCM?

Richard0059

Codes 0171 & 2029 which I know are engine issues ...

Nothing came up on transmission, other than it was in neutral ...

I could run the scan again; what am I looking for?

C230 Sport Coup

PRND error. Definate codes, search my posts, dealt with this.
You need something that can scan the TCU.

tjts1

You are posting genetic OBD2 codes. You need to read MB specific transmission codes off the TCM. Either take it to a Mercedes specialist who has the correct Mercedes scan tool or buy an Icarsoft i980 or MB2.

Richard0059

I have a Icarsoft MB II ...

I'll scan tomorrow & be back with results ...

Thanks for the quick responses

Richard0059

Ran new MB II scan on transmission ...

No DTCs ...

Suspect shifter or some linkage ...

Ideas/thoughts?

tjts1

Are you getting a good connection with the TCM? Can you read version number or actual values? It might be useful to go into the transmission's live data and see what's going on with all the solenoids and sensors. Is the fluid level in the transmission correct? Does it leak?

Richard0059

Yes to both questions ...
No leaks ...
Fluid level good ...

Datastream info:
1) Y3/6s1 (starter lockout contact) OPEN - Which I understand should be open when in neutral
2) Selected gear by means of selector lever (CAN) N

That's it nothing else ...

tjts1

That's that's odd you should be getting a lot more data streams from the TCM.

EDIT: check fuses 55, 58, 61.

C230 Sport Coup

Didi you look under the right floorboard at the TCU? Easy to do pull carpet back, and like 2 plastic screws.
I know you said no leaks, but until you do that, well, you won't really know. Check the cable and TCU for any oil.
New shifter is $700 part, so don't jump to that just yet. Dealer is like twice that.
Worth grabbing at the local pick and pull if they have one...30 bucks.

Richard0059

I'll take a look ...

Thanks

Richard0059

C230 Sport Coup,

I pulled up carpet & checked harness & module; fluid has leaked down harness & it's on the module ...

I didn't pull harness from module, figured I'd google drying out harness & module ...
Don't know if that's possible but just in case, before looking at a new harness & module (I believe module has to be programmed) ...


Thanks again ...

tjts1

I bought my c320 with exactly this problem. The root of the cause is the plug where the wiring harness goes into the transmission. You'll have to replace that.
The way I fixed it is I took the TCM out of the car, took the computer out of it's case and dunked it in 100% isopropyl alcohol. Don't worry this won't damage the computer. Did the same for the case. Then there's some large solder joints where the plug connects to the circuit board. Reflow all those large solder joints with with a solder gun. The wiring harness side of the plug also needs to be dunked in a bowl of isopropyl. This disolves all the ATF. Pull up the whole carpet in the passenger foot well, you'll likely find an ATF puddle under there as well. Once you're done cleaning up, reassemble everything, clear codes from the TCM and engibe with your icarsoft and it should come back to life and shifting normally. If it doesn't you'll have to replace the TCM. It's not coded to the car so any eBay TCM with a matching PN should work.

Richard0059

Fantastic ...

Thanks again

C230 Sport Coup

Another problem solved via the forum. Glad to see you're on the right track!
Interesting how you got no codes! But thats' good news because that means the TCU is
probably still good.I don't think I'd soak it in alcohol, just use some electrical contact cleaner, or
MAF cleaner, which drys faster.

You'll want to replace orings as well, which is what caused the leak.
And do a trans service while you're at it.
Here's a nice kit that has everything from yours truely.
OEM Mercedes 722.6 5 Speed Transmission Service Kit COMPLETE w Dipstick DELUXE!

Most people just clean the harness, check around on that.
Maybe tjt has some tips on replacement if need be.
Always replace the orings when doing a trans service.
2035400253- Connector Adapter with orings or "Pilot Bushing" as Mercedes calls it

C230 Sport Coup

Doesn't need to be programmed but needs to be the same part number (or superceded pn per Mercedes)
There are different part numbers for different rear diff ratios.
Plug and play! You can get 'em pretty cheap off ebay.
Or pull one yourself from Picknpull.

Richard0059

Great info ...

I've been a shade-tree mechanic for years, worked on all makes & models except my one Mercedes ...
Just started last year so I'm sure you'll be hearing from me quite a bit ...



Thanks

tjts1

Yeah so funny story about that. I never replaced the plug, the previous owner's mechanic did along with the solenoids and conductor plate. When all that failed to fix the limp home mode he told the owner it needed a new transmission. At that point he decided to cut his losses and sell it as is. He asked for $1300, I gave him $1100 (02 C320 wagon 146k miles). I had it running 2 days later by cleaning the TCM and a borrowed icarsoft.

Here's some pics of the TCM cleaning.
​​​​​
https://imgur.com/a/PwyRORa

I poured another $2000 into it fixing the AC, swapping AMG suspension and brakes, new tires and a million other small things I can't remember right now and we drove it another 14k miles in the last year. It's my 5th Mercedes and by far the easiest to work on and most fun to drive.

Richard0059

Cool ...

I like that ...

C230 Sport Coup

FYI if you don't know already!
04 1.8L (M271) has a tendency to build up carbon on the valves, and Seafoam seems to work for a lot of people,
proven to work by increased compression measured from before to after.
Left alone it will burn the valves!

AND the single row timing chain stretches. Which then eats timing gears.
When all those things go at once...well...there was a good thread on benzworld once...pics and all. 2-4K to do all of that at once.
Not Mercedes' best engine. TJT's old 6 banger, while having 12 spark plugs (and wires and coils an added maint expense )
and intake manifold issues, is/was a reliable motor capable of going almost forever. 1.8 not so. Well perhaps if you keeps the carbon down and replace the chain everyone 60-80 K miles or so...One guy who mostly did freeway put almost 300K on his till it got wrecked...that was a sad day...we all wondered how long he could go and on the original chain even.
Earlier M111 2.3L like mine has dual row chain which has no issues but has tendency to blow head gasket and blow coolant out #4 cyl on the side of the block...I just keep adding coolant till the day, I toss another engine in since no point in pulling the head at 245K miles.

Richard0059

Latest ...

The transmission fluid had not entered the cable contacts nor the TCM ...
TCM was opened & looked new ...
I read that a part inside the shifter could be broken ...
I'm looking at replacing the shifter, exact part number off Ebay ...

You know of any hiccups I might encounter?