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Key won't start!

2K views 11 replies 6 participants last post by  FATHERTIME 
#1 ·
Hi Everyone,

I have a 1997 SL500, and here is my story.

When I bought the car, I had three keys. Since buying the car, two keys have unfortunately gone missing entirely. I went to the dealer, and several hundred dollars later, I had an extra flip key and a valet key (as the service advisor called it, Mickey Mouse key).

All three keys worked fine, except for the new flip key that I had to initialize the key into the infrared locking system myself with no support from the dealer (dealer said I could take the key home and it would just work, wrong).

The SL went into storage for the winter. I just picked it up and drove it home using the OLD flip key.

So, the other day, my mom had the SL at work and she called me to tell me that the car was not starting. I thought she was crazy and went down there to check. Sure enough, the SL started up on the first crank with the Mickey Mouse key.

Confirmed! Mom is crazy! Or was she. I turned off the car, satisfied that nothing was wrong. I tried the key she had, the old original flip key, which had always worked reliably. The car wouldn't start! She would turn over and crank, but seemed like she wasn't getting gas or wasn't sparking.

Hmm. Take the flip key out, try the Mickey Mouse key again and it fires right up!!

Here is the final tally;
Mickey Mouse key--works in the door locks, starts the engine.
New flip key--works with keyless entry (now), and starts the engine.
Original flip key--works with keyless entry, but won't start the engine successfully.

So what the heck is going on! I can't seem to figure out the right keywords to get successful search results, so I thought I would just ask all of you directly.

Thanks for your help!!
 
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#2 ·
Hi, I'm sorry because I'm not sure what may be wrong with your key, but I also definitely need another key since when I bought mine it only came with only one (flip) key (no "mickey mouse" etc.) all others were missing, so given your situation this got me thinking about a potential problem I may also have in the near future... By the way, how much was a new flip key? Here in Greece the dealership price is 250Euros...
 
#3 ·
There should be a small transponder chip embedded inside each key which is programmed by MB to start the car.

Without transponder car will crank but not start.

So looks like there could be a problem with the transponder in your old flip key.

Did the dealer (or someone) remove the transponder from the old flip key and put it in your new key?

Or maybe the memory slot in the controller (in the car) has been deleted for the old flip key by the dealer?

Or maybe the transponder in the old flip key has been damaged somehow.

This is extent of my limited knowledge.

PM Deplore. He can reprogram etc. very knowledgeable.
 
#12 ·
There should be a small transponder chip embedded inside each key which is programmed by MB to start the car.

Without transponder car will crank but not start.

So looks like there could be a problem with the transponder in your old flip key.

Did the dealer (or someone) remove the transponder from the old flip key and put it in your new key?

Or maybe the memory slot in the controller (in the car) has been deleted for the old flip key by the dealer?

Or maybe the transponder in the old flip key has been damaged somehow.
I had this problem on my 98 SL500 it turned out the the chip in the fob had come loose and was not it the correct location to start the car. I would open it a see if it's in the right place.
 
#4 ·
fredrickjohnson- It sounds like in your old original flip key, the transponder might have failed. The transponder is a little hunk of plastic with a chip inside. It sits inside the key fob near the ignition switch ring. It is independent of the infrared circuit board and is passive, it gets it's power from the car. That woul be consistant with the symptoms you describe. I am in the same boat as you because the only key I have for my car is a rickety original that I am afraid will fail.

S9V9F- I was born in Thessaloniki! Where in the city do you live? My grandmother still lives on Leoforos Stratou. When I was little we lived on the intersection of Delfon and Pariskevopoulo. And to answer your question, I think the flip keys are $300 here in the US.
 
#7 ·
S9V9F- I was born in Thessaloniki! Where in the city do you live? My grandmother still lives on Leoforos Stratou. When I was little we lived on the intersection of Delfon and Pariskevopoulo. And to answer your question, I think the flip keys are $300 here in the US.
Hey Roger, wow unbelievable! I live in Panorama. I drive almost every day by Leoforos Stratou on my way to and from my office. If you happen to be in Thessaloniki let me know and we can go for a beer! By the way, today I had a new key made for me by an independent locksmith. It's a simple "Master" key, but fortunately it unlocks doors,trunk etc. and starts up the car. And for 10 bucks I'm happy.

On another note, if you think that Mercedes keys are troublesome wait until you experience the "Range Rover experience"...:grin I have a Range Rover, they're beautiful but insanely unrelieable. Every once in a while the flip key simply wont start the engine and I have to go through a pretty complicated procedure to re-activate it...
 
#6 ·
I'm sure deplore will know for certain, but can you programme the keys with a STAR SDS system?
I have a Ssangyong Rexton (don't ask :) ) and I also have their Scan-100 diagnostic tool. With this I can programme the immobiliser chips in the keys which I had to do recently when I changed the ECU. So maybe STAR SDS can do the same?
 
#9 ·
Anytime man! Yes it's a very beautiful city, not too big and not too small, perfect "human living conditions" and don't forget Chalkidiki the "Miami of Northern Greece" with some of the cleanest and most beautiful beaches in the world, haha! Unfortunately due to the financial crisis things are a little bit hard, so in that respect you're very lucky to be in the US. Guess the grass is always greener on the other side... :grin
 
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