Evap Emissions leak said to be "electrical fault"
 

My 98 C230 has been giving me some trouble with a leaky evap emissions system lately. Hooked it up to SDS today and no parts read as faulty, instead it showed "electrical system fault."

Now I'm stumped. My tech can't get the car in until the 28th, but thankfully this does not effect the driving of the car.

It has a new shut-off valve, underhood valve, fuel level sensors and gas cap, and SDS reads the components fine. Time to set fire to the car...

what actual value does it give for the tank pressure sensor? should be close to zero with the gas cap off

Mercedes should not bother to issue a message like this, In a modern Mercedes I pretty much expect the electrical system to be malfunctioning at any given point in time. A better warning message would be "electrical system working normally"

Is the check engine light on or is the reserve light blinking?

Funny, but sadly true.

Both.