Is there a way to diable it? When the engine is not running my navi screen keeps shutting down.

 

No way to disable it--it's designed that way to save your battery. I'm not 100% positive but I believe if the key is in the II position (where the gauge lights self-test and the fan blower works) it won't auto-shut down, but there's a lot of stuff on (fuel pump, etc) at position II that can really drain your battery so I wouldn't recommend operating it in position II for long periods of time without starting the car first.

 

Like said its not possible its designed that way to save battery.