e320 1994 check engine on
 

my check engine light came on
Read the codes and I got 5 and 7 at the build in led.
Where should I start?

Build the scanner tool, and interrogate further.

Arthur's scan tool: http://members.aol.com/ajdalton7/ledtool.jpg

JimF's site to give you some insight as to what the codes mean:http://pages.prodigy.net/jforgione/MB_S500.html (see the Diagnostic Module code - section 6 for current codes)

I got the pulse counter, and I did check but no codes on other pins

Radu, if you hear a buzzing from behind the battery I'd suspect a bad OVP relay.

You have an EGR problem. Do a hand vacuum test at EGR port at idle and see if engine attemps to stall. First Suspect on 104 is blocked EGR tube at head.
Search EGR..tons of info on this common code.
Recheck pin 8, as you also have an Ignition code

Indeed there is a buzzing noise that I hear if the engine is ideling and a/c and radio are off so I could differentiate the noise. So I should go for OVP relay.
But I have no other typical symptoms for OVP. Are you sure?

What do you mean by hand vacuum test?... I guess that I will read the posts first.
Did recheck pin 8 got code1
Also my ASR problem reappeared even after I change the brake light switch.
and I got now codes 2 and 14 at Pin 14.
Maybe those defects will correlate somehow.
In other order of ideas, the car runs beautiful no smoke, no MPG increase, clean tailpipe, and plenty of power. The only think that bothers me is the crazy ASR and Engine light.

Well, the CE is an EGR code and 14 is the CTP switch...so, you have to go test them , as I recommended..there is no magic wand or they do not go away with a simple code clear.
I posted to get the codes from 14 a week ago for your and your responce was you didn't have a pin 14 connection..well, now we know you do.
Do the test and then you will have info that will determine the faults and the remedies...
The Search Feature has all the EGR info a guy could ask for.
I posted one for you..now you have to test it.
The logic behind my test are so you do not think that an EGR code means you need an EGR valve...you can put one in, but I will see you right back with the same code in a few days... an egr code means the egr SYSTEM is mal-functioning, due to one of many, many possible reasons,,,do the test I recommended and I will then use those results and that info to advise you on the proper diagnosis. or just use the search feature ..it is right there..from the test, thru to the remedies ..many times over....

Radu, my parents' 1995 E320 had both the Check Engine light lit and buzzing from behind the battery. I swapped the OVP relay from our 1995 E320 and that solved the problem so I replaced their OVP. When the Check Engine light initially came on the engine ran fine, but it soon began to run rough and perform erratically so I knew it was more than a leaking gas cap seal, etc.