P1856 ошибка мерседес w220

That’s a bit of a bummer, driving to work and the car stopped showing the C/S option on the dash as well as the current selected gear.

Read the codes and got:

P1856 Selector Lever Position Detection Has Failed
240C No CAN message was received from control unit A80
2226-1 Transmission Control ETC Fault 9

Sounds all too familiar as I did a mates Electronic Selector Module on his SLK only a few months ago with same/similar codes.
Perhaps it’s some sort of virus that has been passed onto my car.

Cleared the codes, drove for a but but they returned.
You can’t shift from D to R etc. when it has the fault with the engine running.
You can turn the engine off, put it in Park then start and select R from there but once you select D you then can’t get R again unless you switch off.

So I’ve pulled the centre console and ESM out and stuck the one in out of the E55 for now, not showing any errors for now.

Looks like I may need a new ESM.

Anyone know what the extra two pin cable above the ignition switch connection on the E55 Electronic Selector Module is for?

Not got this on the E220 (does not have keyless go) ESM so I’m guessing it may be for the keyless go button on the stick.

Module been good so far so will see how it is tomorrow on way to work.

Anyone here?

New (out of E55) ESM not thrown up any errors thus far, will test for another couple of days, time will hopefully tell.

Decided to strip the original ESM down to have a look see.

A little bit of wear on the slider contact but still a good bit of contact surface left.

The joints on the phototransmitters (Vishay TCPT1200) didn’t look all that healthy, have cleaned the slider contact and resoldered the joints.

On closer inspection of the slider spring contacts though it could be seen that these were not all at the same level. May be just a red herring but you never know.

Adjusted these a little, cleaned the contacts and put it all back together.

Will give it a go and if it still fails after this may try replacing the 4 x phototransmitters as a last resort before looking towards a new complete unit.

Hi,
I think diagnosing electronic faults at a component level is very difficult these days. You need a multimeter for most components and an ESR meter for the capacitors.
I think you are lucky to have the E55 to use parts for diagnostic purposes.
You might have got away with cleaning and bending the contacts, but the optimum pressure settings are very precise. If this works then you will for sure be a happy bunny!.
I think you may be prudent and be looking on Ebay for a replacement unit, although mostly they want to sell you gear selector also, but you may find a module on its own. The only way thy seem to get ruined is by people spilling sticky drinks down the hole.
Replacing the Photo Transmitters may be a possibility, but where to get them from these days unless you have a trade source.?
These days for scanning circuit boards I bought one of the very cheap USB microscopes off of Ebay, and they work very well for what they are.
Best of fortune with your repair.

Steve.

Hi,
I think diagnosing electronic faults at a component level is very difficult these days. You need a multimeter for most components and an ESR meter for the capacitors.

That’s one thing we are quite lucky with Steve, our day job is designing and building electronic circuit boards.
eg

So we have the odd bit of test equipment laying around.

We once many moons ago did the first digital tv box for the BMW 7 series.

I think you are lucky to have the E55 to use parts for diagnostic purposes.

Yes but don’t tell Alps I’ve nicked it.
Was sensible though given it was sitting and it’s only 10 minutes to pull it out.

You might have got away with cleaning and bending the contacts, but the optimum pressure settings are very precise. If this works then you will for sure be a happy bunny!.

You never know, can’t be any worse at the end of the day unless it wont work at all.

I think you may be prudent and be looking on Ebay for a replacement unit, although mostly they want to sell you gear selector also, but you may find a module on its own. The only way thy seem to get ruined is by people spilling sticky drinks down the hole

Yes exactly, entire unit for around £130 would be way to go.

Replacing the Photo Transmitters may be a possibility, but where to get them from these days unless you have a trade source.?
These days for scanning circuit boards I bought one of the very cheap USB microscopes off of Ebay, and they work very well for what they are.
Best of fortune with your repair.

We buy a «lot» of parts, that particular one is End of Life but we would simply cross to another device, worth a shot at the very least.

Out of curiosity, who made your ESM? Cherry?

Out of curiosity, who made your ESM?

Electronic module is marked (among other things)

A2115452932 / Delphi PP 211 267 037

?

Electronic module is marked (among other things)

A2115452932 / Delphi PP 211 267 037

?

I see. So it’s Delphi. Mine was made by Cherry (German manufacturer).

Thanks Steve.
I’d probably look out for one with keyless too though as that would also do the E55.

ESM been ok so far so fair to say that it certainly is/was the ESM and not wiring etc.

Put the old original ESM back in today, had a couple of runs and not seen any errors so far, will test further to see how it goes.

If moisture has got into it, which happens with drink spills and valeting, the selector module is probably knackered, and on its way out.

No moisture, no spillage.

One week in and no errors and I’ve purposely done more miles this week picking kids (grand) up.

I’m pleased so far.

Fitted the centre console back in today after not having any problems for 12 days.

Fingers crossed this has fixed it.

I know what I’m doing this weekend

Anyone here?

New (out of E55) ESM not thrown up any errors thus far, will test for another couple of days, time will hopefully tell.

Decided to strip the original ESM down to have a look see.

A little bit of wear on the slider contact but still a good bit of contact surface left.

The joints on the phototransmitters (Vishay TCPT1200) didn’t look all that healthy, have cleaned the slider contact and resoldered the joints.

View attachment 80156

On closer inspection of the slider spring contacts though it could be seen that these were not all at the same level. May be just a red herring but you never know.
View attachment 80163

Adjusted these a little, cleaned the contacts and put it all back together.
View attachment 80164

View attachment 80165

Will give it a go and if it still fails after this may try replacing the 4 x phototransmitters as a last resort before looking towards a new complete unit.

So my question is how did you separate the gear selector to pull the module out. Seems to be adhesive. I tried heat but it didn’t work

It’s 18 months since I took mine apart to fix it. It came apart easily, but IIRC there is a a connector that needs to be un-clipped that is hidden inside the casing. I think it connects the ESM to the detectors for the +/- gearstick operation.
Ian.