Lexus GX470 Map Light Bulb Size

The Lexus GX470 map light requires a bulb size of 57 for the interior lighting system. Data for the specified component covers the period from 2003 through 2009.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Size
2003-2009	57

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA9s base. 12V, 1W.	57

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Additional Notes

The Lexus GX470 uses the 57 bulb for the map light across all model years covered by the specifications, spanning 2003-2009.
The 57 bulb is an ANSI-standardized type, meaning its designation follows a numbering system governed by the American National Standards Institute and recognized across the United States and Canada.
It operates on a 12-volt electrical system, which is consistent with the standard automotive DC voltage found in most passenger vehicles and light trucks.
The 57 bulb carries a 1-watt power rating, placing it among the lower-output incandescent bulbs used in automotive interiors, which is typical for map and courtesy lighting applications.
The bulb uses a BA9s base, a miniature bayonet-style fitting with a 9mm collar and a single locating pin, which determines physical socket compatibility.
Because the BA9s base is a specific fitment, bulbs with different base types are not interchangeable with the GX470 map light socket, even if their voltage and wattage ratings are similar.
The single-filament construction of the 57 bulb means it serves one lighting function only, with no secondary filament for a reduced-brightness mode.