Brief History: 1998 ML320, daughter ran battery down, upon recharge, crank but no start. After new ignition switch (electrical), fuel filter and pump, determined through process of elimination that key, ring antenna module, or AAM is fried. Ordered new mickey mouse key (valet), car fired right up, no trip to the dealer for any programming; the mickey works right out of the box, if your ring antenna and AAM are sound. Right now it is the only key I have that convinces DAS to allow a start. I do have two remotes/folding keys that work but the DAS chips appear to be fried.

So, I go and order one more mickey. MBUSA tells me that the one I just received is the 8th, and there ain't no more, even if I stomp and roll on the ground. So, putting the dash and stuff back together THE SOLUTION hit me.

SOLUTION: I detached the ring antenna from the cylinder lock, taped Mickey through the ring hole to the ring, wrapped it all in bubble wrap and squirled it away under the instrument panel. You got several inches of wiring. You see where I'm going. Until Mickey gives up his electronic chip soul, any of my DAS-dead keys will start the car, because Mickey is always in the hole. Both my dead keys give me a DAS LED authorization flash when turned, BECAUSE MICKEY IS ALWAYS IN THE HOLE, safely hidden away. So proud of myself, but then again, I can't be that brilliant, so why have I not read this.

Now, even if I lose both of the DAS-dead keys (FOBs with working remotes), I can always get the replacement blade from MBUSA, and mate it to any dummy FOB, at least to unlock driver's door and drive home.

What am I missing here?

On related topics, electrical portion of ignition switch can be replaced by taking off only bottom panel under steering wheel and the trim around the steering wheel itself. A pain but doable, instrument panel does not need to come out, just the surrounding trim. But if you have gone that far, replace burned out bulbs.