I happened upon this post & just wanted to give you info:

I had a dead battery after the ML sat for a long time, then the starting issue as others above describe.

Anyway the bottom line the problem was the Infra Red ( IF ) reader where
the key in inserted into the ignition was not reading the key.

It seems the key was not un-programmed but the reader was
not reading.

So wether the key is programmed or not the IF read is critical
because it is the 1st line to cross before anything can happen.

Once the dealer changed this part all was & has been ok.

This was easily 3 years ago.

 

swirve,

you need the ring around the ignition switch, ie where you put the key in to start. that is the problem. key can only be reprogram to lock & unlock door locks, once key is programed from MBNA for your car it can not be reprogramed for starting of car

 

im going through the same problems, car starts today then dies. will start another day and then wont start after a few hours. have changed the fuel pump after the dealer said it was the problem, cranksensor was changed a few months ago. now dont know what to do. any ideas?

 

I had a similar problem with my 2001 ML430 that was caused by my trying to nudge the remote CD into working. I unhooked my battery to try to reboot the systems and suddenly I had the start and die symptom after I reconnected the battery. I'm thinking, what have I just done to myself? But with some further thought, I remembered that when I got the car, that the battery was dead and I had no trouble starting it with only a minimal charge. The difference was that when I charged it and it started OK, was that the key was already in the ignition. This time I had pulled it out when I unhooked and reconnected the battery. So I went back and disconnected the battery again, inserted the key in the ignition(just in the lock, but not on) and after a minute, reconnected the battery and it started right up and has been perfect ever since. I figure that the system sees whatever is in the lock at the time of power- up, and when there was no key in the ignition, the system would recognize nothing. I hope this helps, and works for you. Denny

 

A few months ago, my husband attempted to start the truck and it hesitated but eventually it started up.. as he was leaving work later that day, he placed the key in the ignition and the truck would not start. the battery was dead. a coworker tried to jumpstart the truck and it started up. the next morning, the truck stared right up, but later that evening, it would not start. this time when he tried to jumpstart it would just make a clicking sound .. it would attempt to start but would never turn over. we bought a brand new battery but it still does the same thing.
we have a mechanic looking at the truck now. he says that we could need a key to reprogram it or we could need a module.
is it possible that the ignition key is no longer any good or is it another key that we need??? i understand that there are different computers and modules for each of them??? could anyone tell me what could be the prob?? the truck has 220,000 miles. its a great truck and it has never given us any major probs in the past. i really love this truck!

 

How do i reset security on 98 ml320

 

Hi there; trust me just change the ignition switch... If you don't believe me just hold it or wiggle it while you start and the truck will run good until you hit a bump. It’s around $50 and it takes 20 minutes to do it yourself.

 

hi guy I have a 98 Mercedes Benz ML320 I got it 2 day - days ago off the lot dealer gave me the car with a bad battery. well I replaced the battery on my own but before that I already had probably with the car dying. we'll lever since I put the new battery in the car doesn't turn its like the battery is dead but isn't completely dead it still powers on it just doesn't wanan turn on the car it turns the inside on but the not the engine it just clicks its not my alternater. any one have a clue what it could be?

 

Easy fix disconnect battery and place key into ignition. Now reconnect battery. Should work everytime

 

Thanks very Much for this info Denny.
I'm going to try this...and I hope I have the same results, Jay.