Lexus LS400 Dome Light Bulb Size

The Lexus LS400 dome light requires a DE3175 bulb size for proper installation within the interior overhead lighting fixture. Available data for the specified component covers the span from 1990 through 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
1990-2000	DE3175

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Festoon bulb, 31mm length, end-cap contacts. 12V.	DE3175

Other Locations

Additional Notes

The Lexus LS400 dome light uses the DE3175 bulb across all listed model years, spanning 1990-2000.
The DE3175 is a festoon-type bulb, meaning it is cylindrical in shape and makes electrical contact through metal caps at each end rather than through a base socket.
The DE3175 operates at 12 volts, which is consistent with standard automotive electrical systems.
The 31mm length designation in the DE3175 specification refers to the distance between the two end-cap contacts, which is the critical fitment factor for festoon bulbs.
The DE3175 carries ANSI standardization for the United States and Canada, meaning the specification conforms to a defined industry standard in those markets.
Because festoon bulbs are seated by spring tension between two contact points, the 31mm length must be matched precisely for the bulb to seat and make proper electrical contact in the housing.
The consistent use of a single bulb type across the entire 1990-2000 production span of the LS400 indicates no dome light socket changes occurred between those model years, making the DE3175 a uniform fitment for all listed years.