hello all,
I have been having a problem with my 1996 c280 involving its check engine light and odb system and really dont even know where to begin to fix it. I wouldnt worry about it if I didnt live in a state that requires emissions testing.

my problem is that none of the cars emissions modules are set when I hook it up to my code reader. my reader doesnt see any dtc's but when i start the engine with the reader pluged in the check engine lite turns on. If I unplug the reader shut off the car and start it again the cel turns off like normal.

It almost seems as if every time I shut off the car the computer gets reset but I dont know how this would be happening, the car starts strong every day. I think I have checked all the relevant fuses and found none to be bad.

Does anyone here have any idea where i could start to find the problem?