Immobilser Code 16

[Dean Waring]

Hi, new member here with an odd problem. 

Ford Focus Titanium, 2010, keyless.

Sometimes ( rarely ) works fine.

Sometimes doesn't respond to key at all, wont lock or unlock, power button does nothing.

Sometimes it will start but immobiliser light will flash rapidly then flash code 16.

And occasionally it will just say key not detected.

Garage said it was the battery, changed that. Problem still persists. 

Anyone have a similar problem and know a possible cause before I end up paying for more repairs that dont solve the problem?

 

Thanks