Check out Jim Forgione's website for a bit on how to read the
trouble codes and reset the light. In particular, at the bottom of
page http://pages.prodigy.net/jforgione/MB_X11.html is a schematic of a
code reader you can make for less than $15 with radio shack parts. The
codes were standardized from 1996 and on, and you can buy OBDII readers
at Autozone and the like for those, but before that, you need to build
your own. It has three leads to connect to the car, a push-button
switch to activate it, and an LED that blinks the codes at you.
Unfortunately, he then wants to sell you a CD with a translation of
what the codes mean! For that, go to
for a (large) .pdf file.
I'm not sure what your connector looks like, but that manual has a
decent summary of the different ones. On my 92 400E, I had a 38-pin
connector, with about ten sockets populated. Two of them are power and
ground, and the third wire goes to the pin corresponding to the system
you are checking. Hold the button for 2 - 3 seconds to start to read
codes. Reading codes involves just counting the times the LED blinks,
and then correlating that with the right table in the .pdf manual.
Then hit the button for 2 - 3 seconds to get the next code, and
continue until the first one repeats. When you want to clear them,
hold the push-button for more than six seconds.
Good luck with your fine car!
67 230, et al