1999 w210. Would unplugging the battery clear the DCT codes? - PeachParts Mercedes-Benz Forum

777funk · #1 12-02-2020, 03:24 PM

I have to pass an emissions test and a check engine will fail it. I believe the issue relating to the code is not an issue any longer.

Would unplugging the battery for a set amount of time erase stored codes?

EDIT: Problem solved. I drove it about 3 more times (maybe 30 miles) and started it a few dozen more times and the CEL went off on its own.

engatwork · #2 12-02-2020, 05:56 PM

I don't think so.

shertex · #3 12-02-2020, 06:21 PM

If whatever it is is no longer an issue, just clear the code.

777funk · #4 12-02-2020, 07:46 PM

Quote:

Originally Posted by shertex

If whatever it is is no longer an issue, just clear the code.

I took it to AutoZone and I don't believe they were able to clear it with their tool.

dieselbenz1 · #5 12-02-2020, 08:32 PM

No unfortunately MB is not like your Jetta where disconnecting the battery also clears the codes, I always liked that feature on VWs. You need a MB specific code reader to clear the codes like Foxwell or Icarsoft or just go to the dealer they will clear it for you.

83w126 · #6 12-02-2020, 09:44 PM

You can clear the emissions related codes with a normal scanner, if it's something else then you need the mercedes tool. There should only be one "comprehensive components" monitor that has to be set to get it to pass the emissions test.

rrgrassi · #7 12-03-2020, 04:41 AM

Quote:

Originally Posted by dieselbenz1

No unfortunately MB is not like your Jetta where disconnecting the battery also clears the codes, I always liked that feature on VWs. You need a MB specific code reader to clear the codes like Foxwell or Icarsoft or just go to the dealer they will clear it for you.

Our '06 VW TDI will not clear codes by disconnecting the battery. I use the Ross Tech VCDS for that and other things VW or Audi.

oldsinner111 · #8 12-03-2020, 05:54 AM

I threw away my check engine bulb in 2009.No problems since

777funk · #9 12-03-2020, 08:00 AM

Quote:

Originally Posted by oldsinner111

I threw away my check engine bulb in 2009.No problems since

In a no emissions area, that's exactly what I'd do! Their machine picks up on the code unfortunately.

pimpernell · #10 12-03-2020, 08:43 AM

Quote:

Originally Posted by 777funk

I have to pass an emissions test and a check engine will fail it. I believe the issue relating to the code is not an issue any longer.

Would unplugging the battery for a set amount of time erase stored codes?

You will erase the codes, but you will also erase all the other information. The emission test will fail because they will pick up on the fact that the battery was disconnected, hence all the usual information will be missing.

argon3030 · #11 12-03-2020, 02:31 PM

Is this the code from another thread, relating to system electrical voltage? If so, a generic OBD2 reader like what Autozone uses will not clear it. You also cannot access these codes via the OBD2 port, you have to connect to the round 38-pin diagnostic port in the fuse box under the hood. You need a code reader that can talk to the other computers in the car too, one that covers this specific make and model - Mercedes w210. There are reasonably priced ones out there, so you may be better served buying your own code scanner. Autel is one popular brand of low cost DIY/enthusiast code scanners, and I can confirm they work on all the computers in the w210. Note that you will need the adapter cable to connect via the 38-pin round diagnostic port in the fusebox under the hood - again, you cannot connect via the OBD2 port on w210 to clear this code. Also, if you go with Autel, you must get their "intelligent" 38 pin Benz adapter ($99), you cannot use the "dumb" pass-through adapter ($20).

Edit: If you're near Virginia, you're welcome to bring it over and I'll clear it for you. I have the Autel MD802 with the intelligent 38-pin Benz adapter.

argon3030 · #12 12-03-2020, 03:07 PM

I took some quick photos so you can see how you need to connect to the w210. Again, the OBD2 port is basically useless on these cars, it can do generic OBD2 and that's it. For everything else, like transmission, hvac, airbags, abs, electrical, etc. you must use the round 38 pin interface.

Here is the 38 pin diagnostic port. Under the hood, inside the fusebox near the brake booster:

1999 w210. Would unplugging the battery clear the DCT codes?-img_20201203_145733.jpg

This is the Autel "intelligent" benz adapter needed to interface with the w210's 38 pin diagnostic plug. There is a cheaper "dumb" 38 pin adapter that does not have the magic black box hanging off it. It does not work - I've tried! Only the "intelligent" adapter with the magic black box will work.

1999 w210. Would unplugging the battery clear the DCT codes?-img_20201203_145559.jpg

And here's everything hooked up and ready for some serious w210 computing action:

1999 w210. Would unplugging the battery clear the DCT codes?-img_20201203_145719.jpg

777funk · #13 12-03-2020, 03:13 PM

Quote:

Originally Posted by argon3030

I took some quick photos so you can see how you need to connect to the w210. Again, the OBD2 port is basically useless on these cars, it can do generic OBD2 and that's it. For everything else, like transmission, hvac, airbags, electrical, etc. you must use the round 38 pin interface.

Here is the 38 pin diagnostic port. Under the hood, inside the fusebox near the brake booster:
Attachment 160568

This is the Autel "intelligent" benz adapter needed to interface with the w210's 38 pin diagnostic plug.
Attachment 160566

And here's everything hooked up and ready for some serious w210 computing action:
Attachment 160567

Wow! Thanks for the pictures and info!!

So in order to lose the battery voltage code, it sounds like it's going to be $100 plus maybe more for the actual scanner? Are there any inexpensive ways to remove the code?

argon3030 · #14 12-03-2020, 03:23 PM

Quote:

Originally Posted by 777funk

Wow! Thanks for the pictures and info!!

So in order to lose the battery voltage code, it sounds like it's going to be $100 plus maybe more for the actual scanner? Are there any inexpensive ways to remove the code?

You're welcome, I just happen to have my w210 parked in my garage for a broken glow plug extraction, so it was already prepared for today's photo shoot.

Probably not the answer you're looking for, but depending on the hourly rates in your area, taking it to the MB Dealer or to an independent MB specialist and paying for 1 hr of labor to clear the code may be the most cost effective route.

For whatever reason, many of the low cost code scanners don't support the w210 chassis. For the few that do, expect to spend ~300 or so for the required scanner, cables, adapters, etc. If you plan to keep your car for many years, this may be a worthwhile investment. You can always resell the tools later on.

777funk · #15 12-03-2020, 03:50 PM

So is a 38 pin Mercedes connector a clue that it may work? I'm going to dig around a little. I may just have to buy exactly what you have and either keep or resell once the code is cleared.

Looks like the Foxwell with 38 pin is $200 approx.