[Mashman]

CA only works with 2 keys at a time, the 2 CA keys with the lowest key number, and are enabled.

When your car was first delivered, it probably came with 3 keys, 2 CA keys, and 1 emergency key. The emergency key was most likely key #1 and the 2 CA keys were #2 and #3. If you lose a CA key, and order another, it will come with a higher key number, so in order to get CA to work, you need to disable the lost CA key.

My guess is that if the key you have is CA, and it works with everything but CA, then you have 2 enabled CA keys with lower key numbers. It's very easy to disable a key, the dealer should do it for free. Call the dealer and tell them you want to disable a key that is lost. You will be required to take all your keys so they can determine what key is lost. Once the lost key is disabled, your other CA key will start working.

If the dealer wants to charge you, it's very easy to disable keys with tool32, so you could do it yourself for the cost of a D/Kcan cable.