That's a sign that the memory chip in your radio has started to fail. There's no code on these radios, but instead they're "married" to the car. If everything is working properly, you can unplug your radio to your heart's content, and the security memory chip in the radio will remember its marriage to the car. You're more than likely going to need to get access to a Tech 2 to re-marry your radio.
Yes, a Tech II is required. Then it's a simple menu choice, no security access required.
You might want to test, while the Tech II is still on hand, if the unit is going to divorce itself every time the power is interrupted. The original unit in my car started to divorce itself even if I disconnected the battery for fifteen minutes. That would have been very inconvenient if I didn't have a Tech II on hand.
Tech II is the electronic diagnostic computer that is used to both find the source of issues./problems (transmission, parking sensors, engine issues, ABS, traction control, wheel sensors etc etc and program features/devices for the car. It's a very advanced "OBD II" tool that the dealership mechanics would/do use.