OBDII Connection
 

What is the difference between the OBDII connection underneath the driver's side dash and the one under the hood on the passenger side. I was thinking of buying the basic OBDII reader at Autozone which fits the connection under the dash. My mechanic tried to read the codes from the connection under the hood but only got an error message. I asked later if the key had to be on the "on position, engine off" position. He said no.

There seem to be several folks who report errors when trying to connect the OBDII scanners to MB cars. In addition, my local Auto Zone says they can't scan my car because it's a Mercedes (I know this isn't true).

Can someone tell us why the OBDII scanners are having trouble interfacing with the MBs?

Interesting question...
 

Maybe others will post with their experiences.
I'm using an interface box that plugs into my ODBII connector and my laptop... runs the tests and displays the info on the computer display. Bought it over the net complete with Windows software.
Works without flaws on my 1996 S500. Reads all the O2 sensors, fuel trim, etc, etc.

For the original poster....
The diagnostic connector under my hood is not ODBII, it is Mercedes specific. Is your underhood connector ODBII?
Fed law states ODBII connector must be near the steering wheel inside the car.
Hope this helps. KenP

OBDII hookup
 

I had troubles also at the AutoZone. However, it was corrected by making sure the key is in the second ON position. Sometimes they won't turn the key far enough. This did the trick for me.

Scanner must be able to read ISO 9141 protocalls [ Euro] for Benz ... if it does not, then it needs an ISO Interface...

[QUOTE]Originally posted by MBDad777
[B]There seem to be several folks who report errors when trying to connect the OBDII scanners to MB cars. In addition, my local Auto Zone says they can't scan my car because it's a Mercedes (I know this isn't true).

They might not have a scanner that reads European cars, different protocol than US vehicles

Can someone tell us why the OBDII scanners are having trouble interfacing with the MBs?

Some scanners are make specific, as stated above, our I/M emissions testing program went to OBD scanning in Jan 03 and we have a 98% connect rate for 300E's with multi-protocol OBD software, I'm not at work or I could find out what protocol MB uses.

All very useful information. Thanks! I'm sure there are many who will benefit from this thread for a long time.

Dan

what about earlier models?
 

Does a 85 190E have ODBII?

I have looked all over for this and never found a good answer. At this point I know you can get something out of the diagnostic port from the car, but I'm not sure what and how.

Can anyone clarify? I'd love to write a lil program that might help everyone get some feed back from the car.

xp

ODBII wasn't mandated until 1996. There are some '95's with it, though, and maybe some other marques that were out of the gate early. In 1985 OBDII wasn't even a glimmer in the EPA's eye.;)

then what do....
 

So what code system does a 1990 190E have? I know you can get codes from them.

xp

Anaolg- flash
201.028? or .029?

Pin 3 -Cal Version