Firstly this is for my (Gerry's and Dave's old) 1995 Mercedes E320 Wagon. It has the 16 pin connector, and I have the little blink box code reader (two of them actually, as I keep one in each car). I had the check engine light come on the other day (right after it rained in CA) and I thought "meh, it is some silly code". So I scanned the codes, and "cleared" them (more on that in a sec) and the light went out. And then one drive cycle later, the light came back on (the red, CEL on the dash all the way to the right) and STAYED ON no matter what I did (even with the key out of the car).
I poked around a bit, and saw some stuff about how it might be the Overload protection relay. So I disconnected the battery, and took a look at that little sucker.
It had some moisture under the plastic flip top "cap" over the 15 A fuse. I took it out, and cleaned it all out with contact cleaner, and let it dry. Then I put the Overload Relay back, and I ziptied a plastic baggie over it in case it was getting moisture from some place.
Everything was good for a bit, and then the lights came back....
Note that the car doesn't seem to have ANY issues. It runs and drives fine, and doesn't seem to have any problems that I can notice.
I just went out and re-scanned the codes, and here's what I got:
Code 17 - Data Exchange between Modules
Code 5 - Left front seatbelt switch
Code 9 - SRS Malfunction or time limit for erasing exceeded
Code 6 - Safety Contact Switch | Stop Lamp Switch
Now, I was able to easily clear the Code 6 on Pin 14, but the others didn't seem to want to clear. Is there some trick to clearing them? The instructions say read the code, and then press the button for 8-10 seconds and it should clear. But when I re-read the codes, they seem to not be cleared.
Ideas? I ordered a new Overload Protection Relay, but it won't be here for a bit. It also weirds me out that a check engine light stays on ALL the time.
Thanks in advance.