Makes sense. Although there is a key it works similar to push button start. Turning the key sends a request to the computer to start the engine. This is why you can let the key go but if the engine is not started the computer continues to crank the engine. The warning message must mean the computer sees your request to start the engine but is unable to do so.

 

Mine had similar problems although I have the 3.7na v6. Turned out to be a broken wire..