Lexus LS400 Map Light Bulb Size

The Lexus LS400 map light uses bulb sizes 57, DE3022, and 194 depending on the specific version of the vehicle. Available information covers the range from 1990 to 2000.

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
1998-2000	57
1995-1997	DE3022
1990-1994	194

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA9s base. 12V, 1W.	57
ANSI standard (US & Canada). Festoon bulb, 31mm length, end-cap contacts. 12V.	DE3022
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 3.78W.	194

Other Locations

Additional Notes

The Lexus LS400 map light specifications span model years 1990 through 2000 and reference three distinct bulb types: the 57, DE3022, and 194.
The 194 bulb is a miniature wedge-type (T10) unit operating at 12V and 3.78W. It uses a wedge base, meaning it requires no separate socket retainer and is held in place by the tension of the housing itself.
The 57 bulb uses a BA9s bayonet base and operates at 12V with a rated output of 1W. The BA9s base requires a twist-and-lock motion for installation, which is physically incompatible with wedge or festoon housings.
The DE3022 is a 31mm festoon bulb that makes contact through metal end caps at each end of the tube. This contact style is specific to festoon-type sockets and is not interchangeable with either the BA9s or wedge base formats.
All three bulb types listed carry ANSI standard designation for the US and Canadian markets, indicating they conform to standardized electrical and physical specifications within those regions.
The Lexus LS400 used the 194 bulb for map lighting across the 1990-1994 model years, representing the longest continuous use of a single bulb type in these specifications.
Model years 1995-1997 specify the DE3022 festoon bulb, which represents a change in socket architecture from the wedge format used in earlier years.
Model years 1998-2000 specify the 57 bulb with its BA9s base, marking a third distinct socket type across the full production range of the LS400.
Because each of the three bulb types uses a physically different base or contact format, none of the three are directly interchangeable with one another without modification to the socket housing.
The 194 bulb draws 3.78W, making it the highest-wattage unit among the three types listed, while the 57 bulb at 1W draws the least power of the group.