I have a 2000 ML55 that has had a multitude of problems (see my previous post ML55 Nightmare). After having $9K worth of work for a stalling problem, the car died again. It would crank but not start. After waiting 5 min. or so, it would start and run fine. MB has the car back and thankfully it happened while they were looking at it. They believe that the key is defective. Apparently, the key sends a signal to the ECU that allows it to start. MB is telling me that since the key is bad, the car is in effect going into "anti-theft" mode and will not start. I asked if the bad key could stall the car while it is running and they say yes. This doesnt seem logical to me. I could see if it was one of the electronic keys on the newer MB's, but I thought that since my key has a pop-out metak key, all the transmitter did was unlock the doors.

Has anyone ever heard of this? Is MB right? This problem has been making me nuts. Thanks

 

Key does lots more than act as a remote. It does many of the things that the later smart ket does. Have you ever thought of trying your other key?? That will give you a clue as to the thought that your key is bad. Could also be the AAM or even the ignition lock.

 

The key on your truck has a transponder in it that is powered by the coil around the ignition lock- like pre-smart key cars. If it doesn't get the correst code sent back- the truck will start and stall immediately (acts like a ballast resistor on an old MB or Dodge). If your car is not firing at all- its not the key. Also, once the DAS signal is approved by the EAM (not AAM on on a 2000), I've never seen one stall- the ME-SFI control unit only responds once to the siganl- is it OK to allow the car to keep running? Keyless go will shot the engine down if the key is not in the car after a period of time, but not the other systems.
I'm assuming they asked for your other key to diagnose this- it's like the first step. otherwisse you have no idea if it is the transponder in the key, the coil, etc. thats not reading. Actually the SDS tells you this- if you don't have both keys- STOP!! if you are diagnosing a ignition switch/DAS issue.

Email me with your dealer info, and I'd be happy to see if what they are seeing makes sense. don't remember where you are, I might even know someone there.

 

I had the exact problem the other day on a 210, turned out one of the ME plugs was only plugged in half way.......