Lexus LS400 front and rear turn signal bulbs utilize 7440 and 1156 sizes for forward applications, with 7440 and P21W sizes for rearward applications. The replacement chart covers 1990 to 2000 model years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Lexus LS400 uses two distinct bulb types across its production run for front turn signals: the 7440 for model years 1995-2000 and the 1156 for model years 1990-1994.
The 7440 is an ANSI-standard single-filament wedge bulb using a T20 base, rated at 12V and 21W. It is the standard for the US and Canadian markets.
The 1156 is also an ANSI-standard single-filament bulb rated at 12V and 21W, but it uses a BA15s bayonet base rather than a wedge fitting, making it physically incompatible with sockets designed for the 7440.
Rear turn signals on the LS400 follow the same year-based split, with the 7440 fitted to 1995-2000 models and the P21W fitted to 1990-1994 models.
The P21W is an ECE-standard single-filament signalling bulb rated at 12V and 21W. It shares the BA15s bayonet base with the 1156 but follows European and international regulatory standards rather than ANSI standards.
Although the 1156 and P21W share the same BA15s bayonet base and identical wattage, they are governed by different standards bodies, which can affect interchangeability depending on regional compliance requirements.
All three bulb types specified across the LS400 range operate at 12V and 21W, meaning electrical load characteristics are consistent regardless of the base type or regulatory standard.
The front and rear turn signal positions on the Lexus LS400 use matching bulb sizes within any given model year, so a 1995-2000 vehicle takes the 7440 at both positions and a 1990-1994 vehicle takes different but base-compatible types at each position.