Rob Ginieczki

I'm a do-it-yourselfer, and got the P0705 code. I've gone online and there isn't much info on this and how to remedy--seems like a lot of guesswork-loose wires, dead circuit, etc. Has anyone had to deal with this? If so, did you take it to a MB Service center or do it yourself?

Thanks,
Rob g

gamma300C

What Sx's do you have...limp mode, doesn't go into gear at all, etc.? Seems like the circuit board on the shifter assembly in the console is pointed to as the failed component in most cases..much less likely is the TCU/ECU themselves. I would pop the shifter off (see YouTube videos) and at least visually inspect connectors/board and clean with electronic spray. If it has failed a new one (not cheap) will need to be paired to your MB I believe by the Dealer.. Hope this helps a bit.

Rob Ginieczki

Basically the car runs fine. I’ve had the code for over 18 months and drive it daily. I think it is just getting a bad read. I’ll look into doing a clean up. Would you suggest a WD-40 type cleaner or something more specific?

Thanks for the reply.

gamma300C

https://www.walmart.com/ip/CRC-5103-...xoCLvgQAvD_BwE

Got this at WalMart....can you clear the code and, if so, it comes back?

Rob Ginieczki

Yup, CRC is the bomb. Got some.

When we clear the code, it comes right back on.

rgfinn76

I have the same error code on my 2012.... What is weird after I clear the code, it will not come back on unless I re-start the car within an hour of turning it off. Meaning I can drive to work, let it sit for hours, drive home and no code. However I can start with no code, run to the store go to start the car back up and get the code to trigger. Very weird.

Anyone know where I can find the part number for a 2012 C250 ?

Mo420

Hi all, just wondering if the OP managed to resolve the issue?

My 2011 C180 CGI recently popped up a CEL, and upon diagnosis, dealer puled out codes P0705 (Selection range sensor A has an electrical fault) and P0606 (Component Y3/8N4 is faulty) and recommended replacing the "electrohydraulic transmission control unit". My car only has 46k kms on the clock and has been maintained religiously by the dealership.

The car drives fine, no jerks and no LIMP mode, and I am not really convinced on the need to replace the whole control unit, given my low mileage. Hoping its probably just a minor glitch somewhere. Regarding the shifter assembly circuit board as mentioned by Gamma300C - I understand there have been a few posts mentioning this in the W203 forums, and I was told the W204 with 722.9 boxes don't have such component - would you be able to confirm this?

Regards,
Mo420

xsever

Does your car have the 5-speed 722.6 transmission or the 7-speed 722.9 one?

rgfinn76

Hi there I just responded in the other thread as my fix was replacing the conductor plate. Take a look here and there is a lot of good info. Your other P0606 code is the TCU module which is part of the conductor plate.

https://circuitboardmedics.com/blog/...view-solution/

Mo420

Hi mate, mine has the 722.9 7G-Tronic

By the way, sweet lookin' C300 you got there! Loving the quad pipes and single slat grille

Mo420

Thank you good Sir for the reply and the article link.

For benefit of others, the other thread can be found here: https://mbworld.org/forums/c-class-w...ml#post8029794

Gaffers11

Hi Mo420,
I have the very same issue as you. Exact same two codes. No problems driving. Just wondering what your specific fix was please?
Thanks!

JettaRed

iTrader: (1)

I know this is an old thread, but for others just seeing this to remember, it's not only mileage that affects certain components, but also age and the environment the cars are kept in. The hot and cold of the seasons, as well as, how often the car is driven, can also affect components.

dunca123

Good afternoon everyone; pretty old post, but I definitely find it appropriate that I comment on this issue.

I just recently purchased a 2007 W203 with a 722.6. While during the first test drive, the car was stuck in gear and was in limp home mode. Unable to go from D to P only D to N unless the engine was shut off. I was assuming a conductor plate. (Came back later with the person having the car idle for a while to charge up the battery.) That test drive was perfect.

After purchasing the vehicle, as soon as I left the location of purchase... Stuck in gear limp home mode. (Same story, can't go into P with the engine running)

Finally after pulling off shortly to fill up, drove fine.

Mile down the road, limp mode again.

Pulled over and tried 3 times cycling the ignition off and on to get the D back in the display.

No avail.

Pulled out my OBD reader and saw it was not a speed sensor like I was expecting but P0705.

After parking it and trying again, everything seemed fine. Just stuck with a CEL that went away after a day of driving.

Battery is testing amazing under load. (Had to test to be sure)

Have the issue again. It's not the conductor plate. Is the shift selection delphi control part.

I made sure my TCM was bone dry. With the issues I'm seeing, it's definitely the sensor having issues.

Crossing fingers my reflow of solder will be the solution. That and cleaning the sensors on the board.

I may make a video, though all credit will go the the creator in Indonesia.

dunca123

Well I Fudged up while attempting to repair the Delphi component.

Removing the component, I broke a tab that slots into the shift rod.

I glued it back in place... As for the solder re-flow. I was using my fine tip and I believe I knicked a top edge of one of the sensors while reflowing a pad.

Now, is reading P and R but definitely messed up N and D.

If you attempt this component level fix, definitely need a finer tip than what I used and a microscope setup.
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dunca123

Glue failed. Piece broke off. One notch is not enough.

Random location given to the based off speed of gear shift.

Annoying mess up on my part. Removing the assembly inside the shifter without damage is my bad. It's a one way clip.

To remove it safely, you must remove the entire gear selector shaft.