Finding a full English manual can be difficult as the device was originally produced for the Japanese domestic market. Official Japanese Manuals : Toyota's official Japanese site Toyota Manuals

Specific codes depend on actual W55 implementation; verify with your manual.

: This usually happens when the battery is disconnected. The system loses its temporary boot data and requires the original "Map Disc" to reload the operating system.

The is a 2005-model double-DIN car navigation and entertainment head unit originally manufactured for the Japanese domestic market (JDM) and frequently found in imported Toyota vehicles. The "19" in your query likely refers to a specific page or section of its operation manual or a technical form related to its maintenance. Overview of the NDDA-W55

This manual is presumed to be the or a specific volume within a series (Manual 19) for the NDDA W55 system. NDDA often refers to standard documentation structures used in heavy engineering, automation, or defense-related equipment.

: This usually occurs after a battery replacement or power loss, which resets the unit's internal memory. The system requires a "boot disc" containing a file named LOADING.KWI to restart.