The Toyota Tundra back up light utilizes bulb sizes 7440 and 921 depending on the specific version of the lighting component required for the vehicle. Available information covers a range of production from 2000 through 2021 to provide technical details for the specified automotive lighting equipment.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Toyota Tundra backup light specifications reference two bulb types across all listed model years: the 7440 and the 921. Both are ANSI-standard wedge bulbs rated at 12 volts, though they differ in wattage and physical size, which means they are not interchangeable with one another.
The 7440 is a T20 single-filament wedge bulb rated at 21 watts. Its higher wattage output relative to the 921 reflects a greater light intensity, which is typical for this bulb type when used in reverse lighting applications.
The 921 is a T15 wedge bulb rated at 16 watts. The T15 form factor is physically smaller than the T20, and the lower wattage corresponds to a reduced light output compared to the 7440.
For the standard backup light position, the Toyota Tundra (2018-2021) uses the 7440, while model years 2000-2013 use the 921, with no overlap between the two bulb types within this position across those year groups.
The outer backup light position on the 2013 Toyota Tundra carries a production date split: vehicles built before August 2013 use the 921, while those built from August 2013 onward use the 7440. This makes the build date a necessary reference point when sourcing a replacement for that model year.
The outer backup light on the 2007 Toyota Tundra is specified with a "From 11/2006" qualifier, indicating the fitment applies to units produced from November 2006 onward, which corresponds to a mid-cycle production change rather than a full model year boundary.
The 2005 Toyota Tundra outer backup light specifies the 921 bulb exclusively for vehicles with a standard deck configuration, indicating that this position may vary by bed or body option for that model year.
Because the T15 and T20 wedge bases differ in size, substituting a 921 for a 7440 or vice versa in a given socket is not supported by these specifications, and the correct bulb type for each position and production period must be matched precisely.