polonerw

I have had the same problem with my 2003 SLK 230. Has anyone else with another model had this same problem with the electric seats and is it located in the same place and same relay part as well?

cjennjr

I just installed the relay in my wife's 1999 C230. The power seats were working intermittently, but since installing the relay, the power to the seats is constant. Plus, a very easy job to do...

rostrom

I'm glad that many of you have found my pics helpful to fix this annoying little problem. I have learned so much from this forum that I'm proud to have given a little something back!

For those needing the part number it is 002 542 22 19 and I got one on eBay for about $35.

I'm certain you could take the relay out, pop the cover off, and fix the bad soldering yourself as noted above. I don't have a soldering iron but for this who do and want to save a few bucks this is a great option.

tedshark

Thank you for the great info, I soldered the relay took care of the problem.

tja623

well thanks for the great input and fantastic pictorial. i had a customer come into my shop today with the same problem. after an hour or so of chasing it down, i was about to condemn the control module, like it was overheating in the hot summer sun. but i just double checked this thread, followed your recommendation, and "VOILA!", both seats seem to be working perfectly. i even set it out in the sun to make sure. it seems to be a successful repair. thank you for making my job a little easier today!

Strykher

I have a W202 2000 C230K. I bought the relay from eBay for like $20 some time ago. It took me about 6 months or so to actually decide to open my trunk, take out all the clutters, and look to replace the bad relay. My seat was working time to time, until I finally had it when my wife uses my car and slides the front seat closer then I would not fit properly in it and can't move it back! LOL. Finally.... last weekend I replaced it. Thank you guys for this input.

One more thing though, the forward and back up options now work, but tilting the backrest forward and back still only works intermittently(mostly doesn't). Is there a different relay for that? Only my driver side is electronic btw, the passenger side is manual.

rostrom

Hmmm, I don't know of another relay. That one should be the one for all seat adjustments (and the headrest, too). Perhaps you have an issue with the switch, as well?

hkhan1

You are a life saver, Thank you very much for sharing the info. It work for me.
Thanks,

MB99

On my 1999 C230 Kompressor, the power seat controls worked intermittently then it stopped working altogether. Thanks to this thread the controls work again. I would like to contribute this solution.

Use Rostrom's pictures to locate the relay and carefully pull it from the socket (you may need a small flathead screwdriver). The one I have has the part #002 542 2219.

Use a small flathead screwdriver and gently pry the plastic housing off.
Work on both the left and right sides, not the top(label) and bottom.



Pry this side and the opposite, about 3mm deep.

Examining the circuit board, you will be impressed by its workmanship. No solder cracks. This part will survive a nuclear blast. It is unlikely to be the cause of the problem.




Mercedes Benz-worthy

Underneath the control board, you will find the electromagnet and the contact switches.



Note the contacts at center of the photograph.

A relay is an electromechanical switch. A small current is supplied from the seat controls to the electromagnet. The electromagnet will close the switch which will deliver a large current to the seat adjustment motor. The motor has a large inductance. When the current is suddenly interrupted, high voltages are developed and arcing occurs (similar to pulling the power cord from a running electric fan and observing arcing at the plug). Over time, the contact may corrode and may form an intermittent connection.

Clean the surfaces of the contacts carefully. (There is another set of contact surfaces hidden from view in the photograph.)
You can use a thin (2mm) piece of 1000 grit sandpaper from a hardware store or a piece of printer paper (2mm) soaked in alcohol.

Temporarily replace the cover (the circuit board will slide into grooves in the casing). Don't snap it shut yet. Test it in place. If you are satisfied, then secure the relay housing.

Friska02mobilNy

Thank YOU! so much. I hope I can fix my 99 C230 Kompr soonest. the dealer said it was just sticky, but it is a recurring problem, so, remove and replace is the way to go, I hope. Thanks again.

j_nolesfan

I have an 07 C230. I took the carpet out and removed the plastic trim but my trim is different. It has two locking pins. I didn't see a relay after pulling the plastic trim. In order to expose anything else, I would have had to remove large nuts from the rear edge of the spare tire tray and take out all of the spare tire housing as best I can tell. I did check one parts site and it mentions a comfort control relay. I just don't know where it is in my car. HELP! UPDATE: Could my car have this relay under the hood? Would it still be for the same function?

lordofthering

All I can say is all photos on this thread is for W202 car, you car may have something else.

twuchte

I followed your advice on replacing that seat relay and it worked like a champ, thank you so much. I must have asked 5 different mechanics and they all wanted me to remove the seat and mess with the motor under the seat! $32 and 15 minutes...Done.

mickey13

So I tackled this today. The seat working on and off was really annoying and this seemed like a really easy fix.

Sorry the picture is so bad, but the cracked connection is circled. The other connections were fine. The biggest problem I had was finding my soldering iron, which I couldn't so off to walmart to buy another for $10.

If you've never soldered before, it's really easy in fact. Just get it really hot and scrape off the solder that is already there. Make sure the new solder you use is OK for electrical work (it has to be resin base). And so once you have the connection cleaned up, take the tip of the soldering iron and press it against the component you want attached to the board. Let it get hot, then take the solder and also push it against the component with care not to let the solder touch the soldering iron. The soldering iron will immediately melt the solder and give you a bad connection that is likely to crack again. So the key here is to get that little tooth really hot enough so it will melt the solder on its own. Once that happens. you'll have a good weld.

I don't think anyone explained that in the thread so I wanted to chime in. I have a picture of the repaired relay but it's blurry and I was excited to test it out so nothing good to post. But the seats worked immediately so I'm guessing that was it.

BTW, I did burn my finger pretty badly in the repair, not that I need to go to a hospital or anything but it will hurt for at least a few days so be careful as even someone whose done it before can get hurt.

compress ignite

Thanks Guys (And Gals)

We're "Messing About" with a W210 [1996] Diesel (U.S. Specfications)

That "May Be" (If It's even Possible) "Phantom-ly" operating it's own
Passenger side front Seat [With no Humans present] and thus depleting
the main Battery.

Short of having a "Go Pro" type camera (operated by motion) watching the
seat overnight...

A couple of times the chassis has been found with the passenger seat fully
forward.And no humans have operated it.

__________________________________________________ __________

It's been suggested that a rather super expensive micro-amperage tester
(Like about 2500.00 USD) will reveal all ... [But forget that]

The same entity suggested testing the relays involved for Thermal emissions
But that's just as expensive.
__________________________________________________ __________

I'm liking the Theory that there's some kind of carbon buildup in the Actuating part of the Relay that allow intermittant "Self Operation" of
the relay and thence the Seat Motor.

mickey13

I just ordered a new one because the connection broke again. Might be the Northeast weather or whatever but I do not want to burn my finger again nor continue re-soldering this thing every 6 months.

rziesing

The advice above to remove trunk rug and plastic panel behine back seat to find seat relay is spot on. I took mine out, pried it open
and reflowed all of the connections. (a couple were visibly bad under 10x magnification). Replaced and the seat gremlins are gone.
Spot on advice. Thank you so much.

CigarXO

I have a '95 C36 AMG. My driver's seat will motor fore and aft, and raise/lower under my knees (front of seat); but, the rear of the seat will not lift and the back of the seat will not tilt fwd or back, nor will the headrest motor. On the Pax side, the seat moves on all axis: fwd, aft, front of cushion up/down, rear of cushion up/down, back of seat tilts fwd/back and headrest motors.

I have teen daughters driving so we need to be able to raise/lower the driver's seat.

I swapped the Relay Electric Seat Adjustment OEM 002 542 22 19, in the trunk from Left to Right, but the seats behave the same. Fuses in trunk and under hood appear to have continuity.

Can someone offer next steps in diagnosis?

Thanks,
CigarXO

I exchanged the white ones, no behavior change. I know I replaced the green on in the past, but I think that was a different repair...

spaldingclan

anyone know where the convenience relay for the drivers seat adjustment is for a 2003 c320? it doesnt look like its in the trunk

William Cauble

Rostro,. I also have a 2000 C230 with intermittent seats. I found a singular relay assy/housing under the trunk's plastic tray.. it appeared to be half way plugged in. After fully seating the plug into the relay housing, seats improved but it 's not 100% . I want to be sure I am working with the correct assembly, In an old post you responded to, you mentioned a photo of the assembly. Is that something that you can share with me? IF so, many thanks. UPDATE: I actually logged in as a member and suddenly.. tada the photos from MB99 are being displayed. This is the same black relay assembly that I found not fully plugged in. So my next step will be to unplug it, open and examine/reflow connections. thanks anyway . everyone stay safe out there!
W. Cauble email:williamcauble@hotmail.com

hamadjassiim

I have the exact same issue both passenger and driver seats stopped working completely! checked all fuses and replaced the relay with no luck. please let me know if you know the solution to the problem