Mazda CX-3 Back Up Light Bulb Size

The Mazda CX-3 back up light utilizes a 921 bulb size for the specific lighting component located at the rear of the vehicle. Data for the bulb specifications covers the range from 2016 through 2021.

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
2021	921
2016-2019	921

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Wedge bulb (T15). 12V, 16W.	921

Other Locations

Additional Notes

The Mazda CX-3 uses the 921 bulb size across all listed model years for the back up light position.
The 921 is an ANSI-standardized bulb type, meaning its specifications are governed by a recognized North American standard applicable in both the United States and Canada.
The 921 bulb follows the T15 wedge form factor, which refers to a tapering plastic base that presses directly into a socket without requiring a separate locking mechanism or bayonet pins.
The 921 operates at 12 volts and draws 16 watts, figures consistent with standard automotive low-current lighting circuits.
The 921 bulb size applies to the 2016-2019 and 2021 model years of the Mazda CX-3 back up light position.
The T15 wedge base is a widely used automotive socket type, and fitment depends on both the base form factor and the physical size of the bulb body fitting within the housing.
Because the 921 is an ANSI-designated bulb, aftermarket and OEM replacements carrying the same designation are expected to conform to the same electrical and physical standards.