AMX240 Audio Panel : Bluetooth Pairing???

We just installed a new AMX240 in our Cessna 182. I was checking it out on the ground yesterday for the first time.

Neither the installer nor I was able to get it paired with a cell phone using Bluetooth.  We used two different phones. The phones could see the AMX240 but gave an "incorrect code" message. when we tried to pair.  I know that the AMX240 authorization code is supposed to be 0000, but neither phone gave us an opportunity to even enter the code. They just showed the error message as soon as the AMX240 was selected to be paired.

Is there some sort of trick to this? We did not have a headset plugged in. Could that have caused problems? The AMX240 manual doesn't show any setup options. What's going on???

Thanks

Mike