Start the vehicle, and at the disclaimer screen use the navigation display hard buttons as described below:
Make sure the battery is in good condition then press and hold the three buttons (MAP/GUIDE, MENU, and CANCEL), and keep them pressed for about 3 seconds. The display screen will go directly to the Select Diagnosis Items menu shown below.
Self-Diagnosis Mode (runs the automatic diagnosis of the navigation system)
Detail Information & Setting (allows you to manually diagnose the navigation system)