Rutland75

Today on my CLK 280 2006 I tried the operation of the extra ignition key/switch and I found that the key works the car locking and unlocking procedure and the red light illuminates to signify a good battery but when insert the key into the position on the dash you cannot start the engine.
Using the first/ other key when inserting it in its position in the dash there is a clicking sound and the lights on the dash are illuminated but with this key there is no such operation.
Any ideas what could be the problem?

Plutoe

Very simple---faulty key--remember the batteries are not apart of the DAS.

Rudeney

The DAS (Drive Authorization System) function of the SmartKey is powered by inductively by the EIS (Electronic Ignition Switch). There is a small coil on the SmartKey's circuit board that often comes disconnected due to a weak solder. If you are so inclined, you can remove the circuit board from the key and check this. If not, then you can transfer the EEPROM from your bad key to a "donor" key and that might fix it. Otherwise, you have to go to the dealer's parts department and order and extra key, about $200.

Rutland75

Thank you both for your info:/advice I did try to remove the circuit board but it did not want to come out of the housing without doing some damage.
Is there any information on how to satisfactorily remove the circuit board?
As I require the key for my trip on Thursday I have ordered one from the dealership. VOR, should be here tomorrow (I hope).

Rudeney

Based on your model year, I assume you have the chrome key with a round panic button? If so, once you remove the battery carrier, you can see the circuit board in there. You may see a small black plastic tab sticking up. Just use some pliers to pull gently on that. Now, if you have the newer style key with the triangular panic button, that one cannot be disassembled.

Rutland75

Rodney, I have the key in front of me and there appears to be no panic button.
The key is a chrome surround with the Mercedes logo in the centre (the logo does not move), the top half is the locking button and the lower left is the open button, the right side is the boot open button. No buttons on the reverse.

Rudeney

Oh, you must not be in the USA because all of ours came standard with the ATA (alarm) system where it was optional in other countries. You should update your forum user's profile to include your location (at least country).

Anyhow, maybe you have a newer key which cannot be disassembled? When you replace the batteries, do you pull a tray out of the end of the key, or does the back cover pop off? If it has a back cover that pops off then you have a newer style key that cannot be disassembled.

Rutland75

Rodney, My location has always been on my profile, I am located in the Isle of Man, UK, for some reason my location has been identified as IM for some reason. I have modified this to include the UK.
I had another look at the key today and following your advice I was able to remove the circuit board, on inspection the black coil soldering seemed to be ok but the there appeared some overheating on the metal, I did re-solder the item but the key still does not work.
The new key arrived today after the VOR order, it work satisfactorily I am just £250 lighter.

Rudeney

Ah, I didn't recognize "IM", but I figured you were not in the USA since you had a CLK280 - we did not get those here in the USA.

There may be a way to salvage the old key by transplanting its EEPROM chip into a good key. Here's an thread abut it:

http://www.benzworld.org/forums/c209...-retrofit.html

Dave (a.k.a. 93SoCal400E) has been doing transplants for folks. it might not be worth the trouble th ship back and forth to the USA, but something to consider.