c320-3216

I wanted to revive this thread to see if we all could collectively put our minds together to try and repair our seat control modules.

As the owner of a 2k1 C320 W203, my drivers side seat control went bad. I promptly took it apart and examined it.

Now, I didn't have a digital camera handy, but besides a microprocessor, 3 or 4 capacitors and 7 prominent relay modules, it didn't look all that complicated.

Didn't see any burn marks either.

The 7 relay modules were Siemens V23084-C2001-A403

I found a datasheet in pdf form for the module. Using the 12v power from a molex connector off a computer power supply, I tested pins 1 and 2, and 6 and 7 for continuity. All 7 Siemen's modules appeared to work making a clicking noise when current was applied to each.

I also applied an ohm meter to each relay module and got a reading of .25

I'm not an electrical engineer, but what else could possibly have gone wrong? Do relay's wear out?

C'mon guys, please help revive this thread. Those guy's charging $500 for repair are clearly making out like gangbusters.

06c230hwd

Of course a relay can go bad, all it does for its entire life is complete circuits, thats gotta get pretty boring...

sfkoldun

Well here is my 2 cents. I had "undervoltage consumer defective" too. I did all sorts off tests.
1. measured voltage with car idling, I was getting 13.2, but after couple of minutes it slowly droppes down, I thougt it could the alternator

2. measured voltage with engine off, I was getting above 12 volts, and what I thing the "undervoltage consumer defective" shows up only when voltage drops below 12 volts.

3. next morning could not start the car, the cluster was lighting up but not enough juice to start the car, I got jumpers from other car (not running) cliped the other end to my battery, start the other car let it run for about 5 min, shut it off, remooved jumpers, nad my car CAME UP. Well it made me think the alternator was bad

4. the same day at work I asked my body to help me up, what I was going to do is touse jumpers from his battery to my end and disconnect my battery just to check the alternator. I have told him stories that you do not want to disconnect battery from Benzs at all, as it might give more books to read :}}}. Well I had to step off for a sec. my body was at my car, and guess what hapenned ...... he disconnected the battery.. %&*^#$$%#
The only good thing out of it was that the NEGATIVE CONNECTOR WAS LOOSE ON THE BATTERY

4. Anyway I had nothing to lose, I put connector back on jumped to his car, started his car, let it run for 5 min min, shut down his car, disconnect jumpers, start mine no problem, voltage was about 12.3, which I guess enough to get you start the engine. My next step was to disconnec the negative end from the battery again (my body did it once already anyway .^%&$%&^#@), and if the car is still running that it means the alternator is working, well I disconnecter the negative end from the battery and ..........
........ CAR IS STILL ON, turned on lights, A/C, everything was working with battery DISCONNECTED.

Well it proved me that it was defective battery, which easy DIY (make sure use have some sort of power to the car while doing it) and for some reason it was not charging off my alternator even though it was working. My guess it is because this car have to much brains in it, and it sensed something wrong with the battery and was not giving it juice anymore.

Now the second problem, since the battery got disconnected I have got a message something like that: " elec. stability prog. not availb. ESP " . I was reading other posts where you have to turn wheels all the way to the right and that to the left, drive a bit, and so on the last thing was to empty the ash tray (russian joke). But I was reading one post where the guy found burned out fuse (#62) which was the problem (he also disconnected his battery :}}} ). Well I looked for that fuse ( fuse box under the hood C240 2001 W203) but it was fine, that I was checking the other ones , they all seemed fine. Well the only problem I was thinking of was rear SAM box ( I guess the other name for the FUSE box), as many had problems with it while doing any type of electrical job on the car.

But I was removing fuses with the engine runing (I was not thinking about while doing it as I was pissed off with my body who got me ESP message), when I got back to the car there was 9 foults on display, I was F%%%%, turned off the engine , turned it back and miracle NO FAULTS AT ALL. I do not know what cleared it, but I think while the car was runnig and I was removing fuses ( all clear ones under the hood) and putting them back one at a time, something got reset. Drove it around the coner - no faults

2006c230Mike

Capacitors have a pretty common failure rate. Since this module doesn't seem to last like the rest of the car, I'd change all the caps just to eliminate them. I'd upgrade the voltage ratings on the replacements if they fit and use the 105C degree caps instead of the 85c degree caps that might be on this module. And use 25 volt rated caps replacing the 16 volt. Again, if these replacement parts will fit.

But I never seen this module and am pretty much guessing based on years of electronics work in radio and TV.

I'd loved to hear you fixed this module. Good luck.