Depending on the length of time the power was interrupted, your system may require GPS initialization.

If initialization is not necessary, the system proceeds directly to the Startup Confirmation screen.
If the system fails to locate a sufficient number of satellites to locate your position within 10 minutes, the following screen is displayed.

If you are experiencing GPS reception problems:
A/T Clutch Pressure Control Solenoid Valve B and C Replacement (A/T)
Remove the air cleaner assembly.
Remove the breather hose (A) from its clamp (B), and remove the breather
hose clamp bracket (C).
Disconnect the connectors (A) ...
Radio Theft Protection
Your vehicle’s audio system will disable itself if it is disconnected from electrical
power for any reason.
To make it work again, you must enter a specific five-digit code in the preset
button ...