This week the key has been getting worse and worse. Meaning when I put the key in I was having to play around with it for it to turn, but I would eventually get it to turn. Today I can't for the life of me get it to turn. I changed the batteries in the key and still the same problem. The key will not unlock and lock the doors. The radio plays fine and all lights inside the car turn on, so it can't be the battery. Anyone know what the problem could be? It feels as if the wheel is almost locked. I can go all the way down on the gas and the break is very tight. What can I do?

 

Welcome to the forum.

However, please search the site for other responses to this issue.

In short the batteries in the key DO NOT play a part in the ability of the key to turn.
If you have changed the batteries in the key this MAY explain why you are unable to remotely lock / unlock the doors due to having lost the code synch between the key and the DAS/EIS.
However it could also be a number of other things including the PSE.

If the key won't turn it is likely the EIS Electronic Ignition switch. The key receives inductance power from the EIS and subject to a security handshake a soleoid in the EIS allows the key to turn.
The EIS is a central gateway for numerous pieces of digital data that impact whether the key is allowed to turn.

Best starting place is to get the vehicle STAR SDS scanned by MB and determine what codes have been set. You need a STAR scanner for this not a usual over the counter OBDII compliant scanner.

Finally. Although the fascia warning lights come on when (IF) you turn the key YOU CANNOT CONCLUDE THAT THE BATTERY IS OK.

This site also contains a lot of info re checking whether the battery is OK. Available voltage plays a VERY important part in whether a number of systems operate correctly.

Good luck

Stuart

 

The description is correct, I assume you dont have another key. The battery in the key is for the doors trunk, while the electronic key itself gets energy and communicates thru the ignition slot. The data is processed thru a redundant bus and after being varified the wheel is unlocked and latched. If there is a complete power failure it will not relock as a safety feature.

 

Update. Ok, well this morning I was able to locate the valet key and that worked with no problem. Now that we have this info what could be the problem?

 

KEY

 

Peter, what your saying is that I need a new key? If so thanks for the info. How much do they run by the way and are they only available through mercedes benz?

 

I agree that on the info available it would appear to be the key.
However what would make a key fail in this way? Has it maybe been immersed in water / similar? And why does / did the open/close doors work prior to the battery change?
Something not quite right.

So since another (original) key works fine it is the key end of the system that is wrong rather than the EIS.

Replacement keys work out expensive. The key has to be coded in order to recognise and respond appropriately to the signal it receives from the EIS. This can only be done by MB or at least people with the appropriate SDS diagnostics or similar equipment.

MB charge what they consider to be a "commercial" rate for this operation. I suspect you may not agree with their charging policy!

Good luck.

Stuart

 

I have tried to post but keep on getting error

 

Ok one more try, the key communicates via the collar, to the DAS, I would suspect that if another key works the link is fine. The keys typically are around $200, order an additional key, I had a "bad'one and they tried to order a repacement , (which wipes the other) ittookmy good one, if you are the nervous type they can permanently remove previous keys.

 

Hi Peter.

Did you resize to within the permissable limit?
Are you running a Mac?
I have the same problem.
I left many requests for help from the administrator but the problem persists.

Yes I agree that since one key works the EIS / DAS link is OK.

I wonder what made the other key go bad unless it is a straightforward mechanical (trodden on perhaps?) rather than electrical issue.

Stuart.