Bambino256

W203.052 m272 gtronic trans
yep it happened for the 3rd time in row gear lever can move to the D position but cannot engage the reverse R position
only way to go around it is to cut the ignition step on brake and mover to "P" position then back to "R".Howvere when ignition is activated we go back to same problem no reverse ****...its feels like its locked in D or N only
another thing i noticed on the dash is "Autolights inoperable" displays briefly on the dash.
Could this be caused by low battery problem?? i have approx 100k on the clock

Benzallo

I had similar problems. A new floor shifter gear selector box fixed everything. Mercedes engineers decided a good place for cup holders holding sticky liquids would be right above the gear selector. Even without any liquids spilled into them their life appears to be between 100k and 125k miles.
It's not an easy DIY project but it's doable. The center console needs to be disassembled, which can take some time.
New selectors run around $550 to $700. Used ones on Ebay run about $125 but come with no guarantees. As much labor that's involved in the R&R, I didn't want to be changing out a used selector again 5k miles down the road. It made sense to buy a new one and be good for another 125k miles.
Lots of info on You-Tube for this project.

aromaxa

gear selector. 2 options:

1) get one from wreckers
2) resolder old one on the selector optics sensor - I have done it on mine. Basically it was falling into the limp mode, gear selected values were playing up on the screen, ECU getting confused.

i had to disassemble module and resolder optical channels 4 per sensor as well as baked microchip for 15 minutes in oven

Bambino256

thanks alot folks
with DIY i will make a mess of things do you have any webshops or sites i can go to and make an order for brand new part
European sites are welcome to

aromaxa

I had someone flying to Australia and asked them to bring part from wreckers with them. I take it was ordered locally in the country they were and has been delivered from Latvia to them at the time.

i still have the spare part on my hands, as my DIY worked, if it didn’t I would have used the part I received from Europe. From memory the wreckers price was around $AU120 or roughly around $US85.

Bambino256

hello,
this is awesome so i take it you can sell that part to me and have it shipped to my address
i can provide you with my email address we can discuss further more regarding the same cost for shipping etc....i would not mind buying brand new part too
i went to a Daimler dealership for a diagnostic and sure enough it reported "Selector lever position failed code P1856" with a fat big F no chance for redemption part number required (A 203 26790 24)
then further checks revealed i need upper and lower control arms (A204 330 43 11) (A204 330 44 11) (A204 330 19 11) (A204 330 20 11)...bushes have big deviations all need to be replaced .
finally a bunch of stored codes related to under voltage etc with codes C404 (No CAN message received from control unit ESM N15/5) this looks like i need to replace the battery too which still glows green perhaps the stored voltage is not enough to operate the diff electronic modules hence the faults

aromaxa

hi there,
sure we could do that, just make sure part fits, as I have slightly different number on it to what you have mentioned. It is A2032672524. I’ve done control arms last year via local mechanic, as dealership wanted an arm and a leg for it. Also bushings were ok, but sway bar bushings were off and it looks like in this model sway bar bushings are non-detachable, so mechanic had to order new sway bar from Singapore.

wheel alignment after that as well.

C230 Sport Coup

Wish someone had posted this before.
I had an old shifter with this sensor, but I think I chucked it when I moved recently.
Never heard of any possible fix for the sensor.
Until now.
I went through a couple of junkyard ones, and the last one is good
plus I nabbed another 'just in case' on half price day at PicknPull.
But now I'm at least 100 miles away from a picknpull and not many MB's.

So I'm a little confused by all the photo's.
What was the fix exactly?
You baked it in an oven? At what temp?
Or did you actually solder something?

BTW- Not such a big deal to pull the center console if you know how.
There's a few 'tricks' involved. pic below is part of the pdf posted but the pics got cut off.

aromaxa

both

1) baking part: at 180C for 15 minutes in the oven - just to make sure all the channels refreshed
2) soldering part: renewed/refreshed solder on the optical sensors at the connection points - 4 per sensor = 16 connection points (arrows below)

Bambino256

Alrighty!!
My part number reads A2032679024 (MB diagnostic reads it as MB2095453332 HW version 35.2004 SW version 27.2005)
i hesitated to get that part from you so that i make an informed choice on the part numbers.i came across an OEM website that actually listed the part numbers that preceded the original part number ...but i was still not convinced need to do more research
I checked out a few web-shops and boy oh boy its damn expensive cheapest i was offered was $670 from Amsterdam
i am thinking i should take it apart and work on it perhaps!!!!..... otherwise once i get confirmation that A2032672524 works on the same module as mine i will be in your inbox
thanks for the sharing the info i will keep you posted

Bambino256

hello,
yap after making a pack with God i managed to pry out the faulty ESM

Bambino256

notice the Part Number is A203 267 85 24
has me confused the DIagnostic provides me with a different party number A203 267 9024
i am gona go ahead and follow the pics here and rework the module take me another couple days in between work
i did struggle to get it out however the DIY posted here helped me alot
i am also missing a lock pin cant find the damn thing

C230 Sport Coup

Don't lose the washer that holds the rod in place.
Put a piece of fishing line on it when reinstalling, so it falls off
you can easily try again.

aromaxa

good luck, also if you going to give board a bake, don't sit it directly on oven tray (just to make sure you dont melt anything you shouldn't). Do some sort of aluminium foil legs. I used simple kitchen cooking foil and rolled bits of it in sort of legs/stands and placed board on them through the board holes.

Bambino256

Ok
i managed to find time and get this ESM taken apart on my office desk and lo-behold the optical sensor had the soldered legs off the board .
i used a heat gun to reheat the main board re-soldered the optical switches and the terminals back to the board double checked connectivity although with this particular unit a diode sends an optical signal to another small micro unit
i am guessing this the switching mechanism for whatever function is input from the gear lever or any other control unit
i then took down to my techie to have it refitted while i raced back to work
car is all good now shifting very fine ........you folks saved me alot of money with the DIY and pictures
thank you once again

















dry joints all cleared

Optical switch chips are visible with terminals re-soldered to the board

Resealed with aldite and small touch of bostik glue

both ends sealed

Notice the loose terminals

this is before re-soldering the terminals back to the board


dry joints visible

Delphi chips

reverse side after reheating

aromaxa

Good job mate! Glad it helped! Yeah those sensors work like optical transmitters/receivers, I take it once you put lever in gear, it breaks transmission with the plastic flap, so signal is terminated, this is how ECU knows in which gear you are.

I have been through electrics and even was thinking of changing battery, but after all it happened to be those sensors and joints worn off and needed some re-heating and re-soldering love.

Even though Merc says those modules are not repairable.