The Lexus SC300 brake light utilizes 7440, 1156, P21W, and 1157 bulb sizes for the rear lighting system. Data for the specified components covers the period from 1992 through 2000.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Lexus SC300 brake bulb specifications cover the 1992-2000 model years across three distinct positions: the standard brake light, the center high mount stop light, and the outer brake light.
The 7440 is a single-filament T20 wedge bulb rated at 12V and 21W. It serves as the standard brake bulb on the SC300 for the 1997-2000 model years.
The 1156 is a single-filament bulb with a BA15s bayonet base, also rated at 12V and 21W. It fills the standard brake position on the 1994-1996 SC300 and the outer brake position on the 1995 model and the 1996 model through August of that year.
The 1157 is a dual-filament bulb with a BAY15d bayonet base, rated at 12V with a 21W high filament and a 5W low filament. It occupies the standard brake position on the 1992-1993 SC300.
The 7443 is a dual-filament T20 wedge bulb rated at 12V, 21W/5W. It serves as the outer brake bulb on the SC300 for the 1997-2000 model years.
The 921 is a single-filament T15 wedge bulb rated at 12V and 16W. It is the specified center high mount stop light bulb across all SC300 model years from 1992 through 2000.
The 7440 and 7443 share the same T20 wedge form factor, but the 7440 carries a single filament while the 7443 carries dual filaments. These two bulbs are not interchangeable despite their physical similarity, as substituting one for the other would result in incorrect circuit behavior.
Similarly, the 1156 and 1157 share the same general bayonet base family but differ in base configuration. The 1156 uses a BA15s single-contact base while the 1157 uses a BAY15d offset dual-contact base, which prevents accidental cross-installation in properly keyed sockets.
The outer brake position on the 1996 SC300 specifies the 1156 only through August 1996, indicating a mid-year production change for that model year.
All five bulb types referenced in these specifications conform to ANSI standards applicable to the United States and Canada markets.