15 flashes, your funny. Where are you getting these 15 flashes from? If you want fault codes you need to be accessing the B1 socket under the hood and read them off. They will come in a series of 3 set of flashes like 2-3-2. That would be 2 flashes, 3 flashes, and 2 flashes. If the lights on you a/c control unit are flashing they are doing so to notify you that there are fault codes stored in the control unit and you need to retrieve them.

Good luck
Mark