I bought this car dead and key was with it.
Screen says "cannot see (?) smart key"
I push start button and nothing happens except this message. Do smart keys go bad?
Please list possible reasons.

 

If you look in the instruction manual you will see the procedure to start by holding the fob right up to steering column or in a little slot under the wheel. Try that first. If it works then it's just comms btw the fob and the car. If that doesn't work either then perhaps an ignition or power issue, or wrong fob / not programmed?

 

Double check key battery with a multimeter to verify that voltage is 3v or above. Have seen that many times on xf’s. No secondary key either I presume?

 

What happens too is the battery contacts inside the key fob are rather weak spring metal in the first place and eventually don't make good contact. You can open it up and try carefully bending the little tabs out to put a little more pressure on the battery, but that just weakens them further and will last about a month. A better fix is to put some sort of a "shim" under the battery, maybe .010 to .030. in. thick.