Mazda Tribute Back Up Light Bulb Size

The Mazda Tribute back up light utilizes bulb sizes 921, 7440, 2356, and 2456 depending on the specific version. Data for the provided specifications covers the range from 2001 to 2011.

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
2008-2011	921
2005-2006	7440
2004	2356
2003	2456
2002	2356
2001	2456

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Wedge bulb (T15). 12V, 16W.	921
ANSI standard (US & Canada). Single-filament wedge bulb (T20). 12V, 21W.	7440
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. 12V.	2356
ANSI standard (US & Canada). Festoon bulb, specialty application. 12V.	2456

Other Locations

Additional Notes

The Mazda Tribute uses four distinct back up light bulb types across its model years: the 921, 7440, 2356, and 2456, all of which conform to ANSI standards applicable in the United States and Canada.
The 921 bulb is a T15 wedge type rated at 12V and 16W, and it is the specified back up light bulb for the Mazda Tribute across the 2008-2011 model years.
The 7440 is a single-filament T20 wedge bulb rated at 12V and 21W, specified for the 2005 and 2006 model years. Its higher wattage relative to the 921 means it produces a brighter output.
The 2356 is a dual-filament bulb with a BAY15d bayonet base rated at 12V, specified for the 2002 and 2004 model years. A dual-filament design means the bulb contains two separate filaments within a single housing, each serving a different lighting function.
The 2456 is a festoon-style bulb rated at 12V, noted as a specialty application type, and is specified for the 2001 and 2003 model years. Festoon bulbs are cylindrical in form and mount by contact pressure at each end rather than by a base socket.
The T15 and T20 designations on the 921 and 7440 bulbs refer to their tubular wedge form factor, with the numeric portion indicating relative size. These two bulb types are not interchangeable with each other despite sharing a wedge base style.
The BAY15d bayonet base on the 2356 bulb is physically distinct from the wedge bases used by the 921 and 7440, making cross-substitution between these types mechanically incompatible without modification.
The festoon format of the 2456 differs structurally from all other bulb types listed in these specifications, as it relies on end-cap contact rather than a base socket, which limits its interchangeability with the other bulb types.
The 2356 and 2456 bulbs are specified for alternating model years in the 2001-2004 range, meaning the bulb type changed between consecutive model years during that period.
All bulb types listed across the full 2001-2011 model year range operate on a 12V system, consistent with standard automotive electrical architecture.