The past few weeks we are having problems with starting the car. Sometimes it will give all dash lights, but no start, sometimes no lights and no start, and sometimes key will not turn. Am I correct in my thinking the EIS is failing? I have no plans to remove / repair it, but take it to the dealer for a new EIS, if that is the problem. My "new" key seems to be more prone to this than my wife's "original" factory key.

 

Apartment building people? WTF are you talking about? I'm not guessing. I came to this conclusion through research, forums, and inquiries. Yes, it cost a lot of money to change out the EIS, and if I were 40 years younger, I would attempt the cold solder repair myself to see if that took care of it.

 

What year is your ML?

You probably have already seen this post regarding a similar problem:
https://mbworld.org/forums/m-class-w...rimlims-2.html

My fix (posts 39, 40) did not require any soldering, only a bit of cleaning. You may want to try that fix and see if it helps.