jeil611

Hello, I have 2011 c300 4matic.
My fob key does not lock/unlock the door and not start the car.
I opened the doors with the blade key, and try to start the car but the car does not recognize the key.
I found the post about the red light on the fob key.
I changed the battery of the key, but the red light is still going on.
and it still does not start the car.
I don't know what is the problem.
Is it a problem with the EIS or the fob key?
Thanks.

ItalianJoe1

The key does not flash the red light or does?

Most likely you have a bad key, a faulty EIS won't disable the remote locking/unlocking.

You have your second key right? Try that one, or order a new key. Even if your EIS is bad, you should have a spare key, so if you only have one, order a second one. They come pre-programmed and will work right out of the box but have to be ordered in person through a dealer as they are a Theft Relevant Part and have ordering restrictions.

jeil611

Thanks. But I have only one key cause I got the used car and the dealer gave me just one key....
I asked them to get me the second key, but they said they don't have.
So should I get a second key on ebay or something? or just ask Mercedes?

jeil611

and yes the red light still blinking when I click any button of the key.

ItalianJoe1

You can only order a key from a dealer and you have to prove ownership to do so, all keys come from the lock and key center in texas and are special order and tracked to prevent theft issues.