So, I'm assuming you have MFT and the push-button start (I think all Titaniums have that). Are you just turning on the MFT (pressing the power button on the stereo), or are you turning on the ignition (pressing the start button without pressing the brake, turning on all the cluster lights, etc?)
Reading the forums, you can do the first
to get the stereo on without the rest of the vehicle. If you do the second, you're going to be powering up a lot of other stuff (climate control, fuel pump, etc.) that will kill your battery pretty quickly.