Acura NSX Back Up Light Bulb Size

The Acura NSX back up light utilizes 1156 and P21W bulb sizes for illumination. Data for the specified components covers the range from 1991 through 2005.

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
1991-2005	1156

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156

Other Locations

Additional Notes

The Acura NSX uses the 1156 bulb for the back up light across all model years from 1991 to 2005.
The 1156 is an ANSI-standardized bulb type recognized across the United States and Canada, meaning it conforms to a defined set of electrical and physical characteristics shared by all compliant manufacturers.
The 1156 operates on a 12-volt electrical system and draws 21 watts, which is consistent with standard automotive incandescent reverse light applications.
The bulb uses a BA15s bayonet base, a single-contact fitting where the "s" designation indicates a single pin rather than the offset dual-pin arrangement found on related bayonet types such as the 1157.
Because the 1156 is a single-filament bulb, it is not interchangeable with dual-filament bayonet bulbs like the 1157, even though both share a visually similar BA15 base style. The pin offset on the 1157 physically prevents incorrect installation in most sockets, but the distinction is relevant when sourcing replacements.