722.6 gear shift module repair help

[slapper4]

hi,

ive scanned this forum and the internet, can anyone provide specific instructions:

can anyone advise more about removing and fixing damaged 'gear shift module' / 'selector lever module 'in my W202 c220 cdi 2000

I would also like to know the MB part number, as it is 722.699 transmission(5 sp AUTO - tiptronic), so i can online search/order. maybe there are alternatives?

currently, it's got the classic 'limp-mode' (stuck in a low gear and can only get reverse from P, and P with the key off) and no dashboard gear indicator.

this seems a common fault on other vehicles, the circuit shorts or gets water damage and we are told to have it replaced approx £600 parts plus labour.

have just had MAIN DEALER do a 'star' diagnostic today, very helpful:

P1856-01
P1856-03
P1856-05
selector lever module position detection has failed.

service manager said its probably the gear selector module need replacing.
thats good news for me, easier than dismantling the transmission itself

i searched and found interior photos on this site

http://forums.mercedesclub.org.uk/showthread.php?t=72442&highlight=p1856

this video explaining the cicuit operation is also pretty cool:
http://www.youtube.com/watch?v=qbVJ_p6bTig

but no procedure list for removing or splitting it down
i am an expert engine builder/technician so seems worth it if it's just repairing worn copper tracks and wiper contacts which i suspect.

i think i would remove the surround, and centre console, check for a loose connector first, then proceed release clip from underside linkage, then what?

if this is such a common fault and the damaged bit is cheap, then why are they so expensive new or used~?

so why cant i replace ONE worn electrical wiper under £800?
when its a 12 year old vehicle worth about £1200 fully working !
tiptonic was so rare in a W202, perhaps i can use a 5speed tiptronic lever from another model?

 

[television]

I will be able to print of the instruction for changing the shift module but too late tonight

 

[bigasotonuk]

Hi,
This link shows the shifter mechanism on the Tip box for the 202, with the relevant pt. no.'s.
http://www.neoriginal.ru/cat/mb/part_202033_1_1_44V_202_133_/26_105
I took the pt. no. (item 10 in diag.) and found the price of a new selector which is £412.56 from Inchcape.
Removing the selector assembly I believe is quite self explanatary once you have removed the interior trim and console which is held in by just a few screws.
I have done a bit of research about this, as I have been thinking about converting my AMG to Tip, I had always thought that the selector unit would be the same from a CLK 208 as a second hand 202 item would be hard to source, but apparently they are,nt the same, I think the only option would be to source a new or second hand item.
Good luck with the repair.

 

[slapper4]

progress update

thanks for your help,
i stripped it out and stripped it down and inspected today, was easier than i thought but still no different after the service i did (limp mode, no gear icons)

i am convinced now, that it's not the gear positon indicator literally, but the gear position encoder PCB above it thats corroded and dead.

bear in mind this is the tiptronic selector, and on a W202 very rare, usually these are on the CLK 230 and e-series models after 2000. inside it is different to the internet pics and parts ive seen so far, that apply to non-tip selectors, from outside the give away, is that on the gate label you only have P, R, N, -D+, so if you see P, N, D, 4, 3, etc then it's def not tiptonik (1-touch).



because the tip selector allows stick side movement in D, they redesigned the lever position sensor, by using a 2 track potentiometer, not an encoder. the encoder is i think on the PCB which also carried the LEDs and tip sensor. this cost about £80 but at the moment i dont know how to replace it without breaking plastic tabs , so id like some further advice?

it looks from the parts diagram the gate can be removed upwards somehow, and might be possible without me removing the whole assembly again, then presumably theres a few locating lugs snapping PCB in position and a ribbon cable like you see in laptop keyboards. anyone done this? my guess is before replacing the PCB, its worth removing it, cleaning it up and replacing in case it was just coffee or something on a connector /pcb thats simple. there's a youtube video i linked in my original post, i wonder if that guy's home made test rig leds would work the same with the tiptronic selector external harness connector - if so, it would be possible to test the selector stand-alone. thats useful, because i suspect its possibly ok and the TCU, which would mean i am wasting time and money here replacing the selector electronics.

its annoying the dashboard gear display is just blank, and doesnt say 'F'ault or something, just so you can see the TCU is still alive, but i must trust MB star that is reporting selector malfunction, not TCU function (i assume it could)

I managed to service the lever potentiometer; its pretty easy with a cranked bit of wire to flip the catches off the case with it still on the opened up unit, though its still pressed onto the lever arm, then you can see the contact carriage, track, and connections, and in my case - no dirt, damage or anything looking like uneven wear, so just contact cleaner, drain and replace lid and reassembled the assembly.

prices i am seeing are ;
£90 for a tip' selector encoder board
£250 used selector assembly (but i worry its from a non W202 car and incompatible)
£480 trade MB new W202 unit (MB advised 2022670824 from my chassis no.)

£0 if i can remove and clean connections on the PCB without snapping the case parts(need advice)

Obviously i dont want to replace the unit then find its the TCU or something else. maybe these PCBs are always the culprit on a tip selector, and thats why MB redesigned it easy?? to replace - if you know tell me..

i will try to get advice from the PCB seller or try prising the gate upwards tomorrow, any advice appreciated

 

[television]

Interesting that we have another thread where the brake lamp switch has killed off the Box ECU and now locked up and no display also on a 202 tip box

 

[rsdeepsea]

Just finished replacing gearshift module

I have a 2001 SLK230. The wife opened a drink and spilled it on the gearshift. Luckily it was in the driveway. Went into limphome mode, black square instead of P,R,N,D and at first it wouldn't even start up or shift out of Park. I removed the shift knob, hit the handle with a deadblow mallet until it released, removed all the covers by popping them off. Tried cleaning and drying the PCB. No good it was corroded and nasty.
Bought a used gearbox on Ebay from a CLK230 2000-2005. I just made sure it looked the same, black plastic housing. The others appear to be metal.
Remove the radio, get the tool from dealer for $4.00 (the only thing you'll ever buy cheap at Mercedes!).
Then remove the center console cover with screws under radio and at base of cover.
Remove the accessory tray and ash tray at bottom, remove screws, push left, pull out right.
Then take off cover from E-brake. I sprayed silicone spray in top and let it run down, came off pretty easy then.
Remove two screws from front of center console at the gearshift box, remove spring loaded cover with two screws, and then pull up the carpet flap at back of console to expose to 10mm bolts. Lift console at front about 1 inch, there are downward facing hooks that mount it to the gearshift housing, then pull to aft and lift up and roll over on its side. remove screws holding switches for mirrors and top, and compartment with roll top storage. Phone wires and other stuff just remove. Lift away.
Now you can access the two metric allen bolts at rear of housing, just push the shroud side to side when working on them. Unbolt front metric allen bolt.
Lift up gear shift, slide hand under and grab the gear shift lever, other hand use a flat screwdriver to remove the clip. Pop lever off and lift gearbox. Remove cable with white plastic cover with a flat screwdriver, pop the tabs over, and the piece comes out of the little metal cylinder. Also remove one wire harness from gearbox.
Put new one in, assemble in reverse. Goes back together much easier than coming apart.

When I turned on the car, the tranny indicator showed P, limphome was gone, no warning lights, test drove down the road at 60mph.
Didn't need to clear codes or get anything reprogrammed like I've heard some people mention.
Saved $700 and cleaned all the console pieces to look new. Also take out the roll top pieces and clean them with a toothbrush to get all the grit out of them. Looks 100% better and slides smoother!

Was hard to find a step-by-step, so here it is. Good luck, hope it goes as smooth as mine did!

 

[range rover]

The moral to this story must be 'Don't drink near the driver'.

 

[slapper4]

update - 202 gear shift PCB

thanks for your help,
i stripped it out and stripped it down and inspected today, was easier than i thought but still no different after the service i did (limp mode, no gear icons)

i am convinced now, that it's not the gear positon indicator literally, but the gear position encoder PCB above it thats corroded and dead.

bear in mind this is the tiptronic selector, and on a W202 very rare, usually these are on the CLK 230 and e-series models after 2000. inside it is different to the internet pics and parts ive seen so far, that apply to non-tip selectors, from outside the give away, is that on the gate label you only have P, R, N, -D+, so if you see P, N, D, 4, 3, etc then it's def not tiptonik (1-touch).

just to update you guys,

FIXED
using pcb from an e-class tiptronic gearstick

I bought a 202 tiptronic pcb from ebay portsmouth breaker an indian guy, but it was a dud and he was a pain to refund after opening a case

I was still convinced the problem was only the pcb as its the only thing really vulnerable to dirt i could see, so i took a risk and called/emailed all the merc breakers i could find

eventually first class mercedes said they only had an e-series tiptronic one which had same gate panel byt different housing, but as the housing was damaged he offered it for just £50 not the usual £200. i grabbed that paying credit card and arrived next day. just after its despatch i also ordered the transmission computer for £125 refundable item should i not need it

as i suspected, the pcb inside was identical, and within 30 minutes i had my car back working perfectly phew!


so i immediately cancelled the transmission computer they hadnt despatched and they did a refund. i suggested they take £10 and refund me only £115 but not they said in full

well they didnt , and three months chasing them and getting lies(recorded) and fobb offs eventually my bank refunded it for me, so 2 hours work and months of stress thanks to '1st class mercedes'

to change the pcb you dont need any special tools, but there are click tabs holding the pcb undertray up to the interior you need to free, then its obvious.

Mercedes are assholes for making such a vulnerable part you can change in minutes unavailable new. they knew it wouldnt last so putting £800 price tag on it is cynical.

as i said i found an e series board identical, and its worked for a year now.