Ford C-Max Back Up Light Bulb Size

The Ford C-Max back up light utilizes a 921 bulb size for illumination during reverse maneuvers. Available information spans the 2013 to 2018 range for the specified vehicle lighting component.

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
2013-2018	921

Bulb Specifications

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

Other Locations

Additional Notes

The Ford C-Max uses the 921 bulb for the back up light across all listed model years, spanning 2013-2018.
The 921 is a wedge-type bulb, classified under the T15 designation, which refers to its tubular glass envelope size of 15/8 inches.
Wedge bulbs use a plastic base with two wire contacts that grip the socket directly, eliminating the need for a separate metal base or pins.
The 921 operates at 12 volts and draws 16 watts, which are standard ratings for automotive reverse light applications.
The 921 conforms to ANSI standards and is recognized in both the United States and Canada, reflecting a standardized specification shared across North American markets.
The T15 wedge base format means the 921 is physically interchangeable with other bulbs sharing the same base type, provided the voltage and wattage ratings are also compatible with the socket and wiring circuit.
Using a replacement bulb with a higher wattage than the specified 16W rating risks exceeding the thermal and electrical tolerances of the socket and surrounding housing.