Rick

Ok....so I did it...just for giggles
I bought a key from e-Bay for $19. The seller said it could be reprogrammed, but based on what I read here, I sort of knew better.

I switched the 'guts' of the key with my own, and found that the hatch release button works fine (which was my ultimate goal anyway). But out of curiosity, I called MBUSA, and this is basically what they said:

MB Smart Keys are programmed at the factories for specific cars. 8 keys are made for each vehicle and use PROM technology to hold the encoded key data. This considered, they are one shot programs, and can not be altered. When your dealer orders a key for your car, it's one of the 8 originals. If someone should happen to lose all 8 or damage the ignition, then the entire ignition switch, 8 keys and the cars computer has to be replaced and reprogrammed for the car....specifically....uniquely...and again, only one shot.

Can anyone provide more details?

nevide

better hold on to those keys guys.

midas888

I got a another key for a total of 3... the third one cost $100!

Oh well, nothing beat the look of confusion the other day when I let my friend drive my car. "Where do I stick this thing in? Where's the metal part?"

steffen

I've heard this before - at some point if you exhaust all the keys you end up having to spend $1000's to replace the computer.

But this brings to mind a question - is there some bunker in Stuttgart where all the "extra" keys for each car are stored?
Or (more likely) are the unique codes stored in a computer somewhere and the PROM is programmed with the unique code when you ask for a new key?

--Steffen

FrankW

probably the code stored somewhere. If they store keys for each cars they make, there would be literaly mountains of keys.

the real question is that Is it really possible for some guy to lose 8 keys?

firstkill

has anyone done the pool test on a key yet?
I know a lot of peoples that have lost cell phones to the pool before.

Or is anyone brave enough to give it a shot with their smartkey?


fk

tifosiv122

After 10-20 years and several owners I am sure its possible.

Erik

viper

They don't keep the codes anywhere. The code is determined from a hash algortihm using the VIN number. If someone could determine the hash algorithm you could conceivably make a key for anyones car if you have the right equipment. But this would not be easy.

tberry

Hi Rick, can you be a bit more specific on how you switched the guts of the key? I want the hatch release button too DAMMIT

Lynn

I'm sure the instructions have been posted before. Please do a search.

tberry

thanks Lynn. any suggestion on the search? "smartkey gut change"? just "smartkey"? "modify smartkey"? "myths about smartkey"?....so many options. Good thing Smartkey is more then two letters or i'll be SOL....like my search for C7

Lynn

https://mbworld.org/forums/showthrea...art+AND+Button

JimB

is being stored at Corporate office at Marlton, NJ. That's my Dealer told me when I lost my ML key. which I found it later after I recieved my new key Now I have 3 keys. Smart Keys could be there too

trench

Each key also has a finite life-span. Each time the key is used to start the car the ignition code is changed (I assume to prevent key cloning). There are somthing like 25,000 (I forget the exact number) "starts" that can be encoded to each key, after these are exhausted the key will no longer work.

Davidta

That sounds wierd... If MB were to do something like that then I would imagine they would have to provide replacement keys for free whent hat problem came up, no matter how many miles the car was at. They would be artificially limiting the life span of your car, that is like building a defect into a product to make more money later, maybe after the 25,000 it recycles. Furthermore with that algorythem how could you ensure all your keys would be using the same number sequence to start the car? I would imagine that it has an algorythem that picks one of these 25,000 codes and then both the code they key is giving and the one the engine is looking for would need to match. This is all jsut a guess though, but it would seem to make the most sense from everything I have heard. I am by no means an expert though, I switched my major form computer science after a year.

revstriker

I have a hard time believing that they make 8 keys for every car, and then store them somewhere. That means, they are storing about 6 sets of keys for each car that they sell. More likely they are storing the codes etc. to make new keys, should you loose one. I can believe that this is limited to 8 though.

I also have a hard time believing that there is a limit on how many "starts" you get with a key, even if the number is as high as 10,000.

If anyone has any "official" info on this, please post it. Otherwise, I am just writing this off as urban myth.

Davidta

I don't think storing the keys would be that difficult to do, With the amount of paper work they already need to store 6 keys would not be that difficlut, it would be one small box per car in a warehouse somewhere. This system is probable alot more secure then storing it on a computer by Vin do to the far greater ability to limit access to the space.

trench

The ignition module is encoded for eight keys (or key "slots" if you will), plus two replacements for each key, for a total of 24 keys. The car remembers the code for each key seperatly (and apparantly for the 2001+ models only two of these key "slots" can be used at a time).

So if you lose a key (that has yet to be exhausted) MB gives you a replacement for the one of the slots you already have, which necessitates sticking the key in the ignition for thirty minutes to five hours, at which time the car verifies it is a true replacement key and enables it with the current code (while at the same time it renders the key it replaced non-functional). Once a key is exhausted they send you a key for "slot" #3, which should work immediately without the "programming step."

With regard to the number of starts, I tried to search for the actual number but couldn't find it (although I did find one of my own posts that thought it was "25,000 to 100,000"). It's probably on the high end of this range, even if a car is started twenty times a day (which is a pretty high number of starts per day) then there will have only been ~36,000 starts after five years. Although, this could be as revstriker said an MBWorld legend.

revstriker

I still don't think they would do this. Think of how many cars are on the road at any given time. We're not just talking about one year's worth, but all of the cars. Now even if they could get all of these keys into a warehouse somewhere, why would they? Most cars will never go through all of the keys, so would they just sit in this warehouse, collecting dust forever? My guess is still that they store the info on a computer, and when you need a new key, they can either program a blank somehow, or even create a new one as needed.

By the way, I'm sure most of the paperwork being stored is done so digitally. Plus, they probably have a purge date on the paperwork after so many years. With the keys, they would never be able to purge them.

spacetrain

And for those that are interested in using the sleeve of the key for their coupe. I have one for sale.
It is actually a third key that I have, from a car that was bought back by MBZ. Now I have that extra key laying there.

$10 shipped.
Or you can come by and pick it up if you live near by. I am in Orange County, CA.

spacetrain.ca@netzero.net

Thanks.

Lynn

We now know they would need to make and store 22 keys. Why would MB spend the money to make and store 22 keys for each of the hundreds of thousand of cars per year that they build? We are talking millions of keys per year. The cost would be enormous. The cost of storing the key data on a computer would be comparatively insignificant. And safer. How does a hacker get into a lan that is not connected to a phone line? Or a stand alone computer that is not connected to a phone line?

MarcGetty

A friend works for MB USA and says people loose all 8 keys all the time. He says that almost all of the people to do this are M class owners.

There are 8 keys possible per car, and for whatever technical (not policy) reason, they can't recreate a previous key. I can't remember the details as to why.

See: https://mbworld.org/forums/showthrea...threadid=44800

Matt230K

A customer at my dealer usually gets a new ML and new SL every year. For each car, he always orders two extra keys, for a total of four. But when he trades the cars back in after a year, the two extras are usually still sealed in the same bag from the parts department when he ordered them. But at least he's not losing them.

FrankW

I have a thought. Could it be that MB just made 8 laser cut keys without the SmartKey for each car, and then when people lost'em they grab one of the keys to go with the SmartKey.

Matt230K

Which part of it is laser cut? The metal part? I think you've been watching too much "Gone in 60 seconds".