Lock symbol when I push the power button on my automotive device

The lock symbol signifies that the device has a display lock feature. If you quickly press the power button on the device while it is NOT connected to power, it will go to sleep.

When you press the power button again, the screen will turn on and display a lock symbol.  This is designed to prevent any accidental touches.  To unlock the screen, double-tap the lock icon.

If the device is connected to power while it is asleep, or the bracket is on the back, then pressing the power button will bring up the main menu and the display lock will not appear.