The Nissan NX brake light requires bulb size 1157 or 1156 or P21W depending on the specific version. Data for the bulb sizes covers the range from 1991 to 1993.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Nissan NX brake light specifications cover the 1991-1993 model years, with two distinct bulb positions: the standard brake light and the center high mount stop light (CHMSL).
The 1157 bulb, used in the 1993 Nissan NX standard brake position, is a dual-filament ANSI-standard bulb rated at 12V with a 21W main filament and a 5W secondary filament, mounted on a BAY15d bayonet base. The dual-filament design allows a single bulb to serve both brake and tail light functions.
The 1156 bulb, fitted to the 1991-1992 standard brake position, is a single-filament ANSI-standard bulb rated at 12V and 21W, using a BA15s bayonet base. Unlike the 1157, it carries only one filament and is dedicated to a single circuit function.
The 1157 and 1156 bulbs share a similar physical bayonet base style but are not interchangeable. The BAY15d base of the 1157 has offset pins to prevent incorrect installation, while the BA15s base of the 1156 has symmetrical pins, meaning the two types are mechanically distinct.
The 1993 model year represents a change in the standard brake bulb from the single-filament 1156 to the dual-filament 1157, which operates at a higher combined wattage.
The 921 bulb, specified for the 1993 CHMSL position, is a T15 wedge-type ANSI-standard bulb rated at 12V and 16W. Wedge bulbs use no separate metal base, as the glass envelope itself acts as the retaining element within the socket.
The 194 bulb, used in the 1991-1992 CHMSL position, is a T10 miniature wedge bulb rated at 12V and 3.78W. At that wattage, it operates at a significantly lower output than the 921 bulb used in the following model year.
The 921 and 194 bulbs are both wedge-type but differ in physical size and wattage. The T15 envelope of the 921 is larger than the T10 of the 194, and the two are not interchangeable despite sharing the same base style category.
All four bulb types listed across these specifications conform to ANSI standards applicable in both the United States and Canada, indicating standardized electrical and physical tolerances across that market region.
The CHMSL position on the Nissan NX transitioned from the low-wattage 194 bulb in 1991-1992 to the higher-wattage 921 bulb in 1993, reflecting a change in the light output specification for that position between those model years.