Navigation System Symptom Troubleshooting - System locks up constantly

System locks up constantly Start the engine and turn the ignition switch OFF, then turn the ignition switch ON (II). Does the system reboot?
YES | - | The system is OK at this time.■
NO | - | Check the DVD for scratches or damage and the navigation unit for water damage. If OK, go into the Diagnostic Menu and do all of the ‘‘Unit Check'' tests. ■