Toyota FJ Cruiser back up light assemblies use 921 and 3057 bulb sizes for the standard and outer positions respectively. The replacement chart covers 2007 through 2014 model year data.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Toyota FJ Cruiser uses the 921 bulb for its back up light across the full 2007-2014 model range.
The 921 is an ANSI-standard wedge bulb in the T15 form factor, rated at 12V and 16W, making it a single-filament design suited for simple on/off functions such as reverse lighting.
The outer back up light on the FJ Cruiser uses the 3057 bulb across the 2007-2014 model range, with the 2014 model year specifying this bulb only for units produced through July 2014.
The 3057 is an ANSI-standard dual-filament wedge bulb in the T25 form factor, rated at 12V with a 27W high filament and a 7W low filament, which allows it to serve two distinct brightness levels within a single housing.
The 921 and 3057 are not interchangeable. The 921 is a single-filament T15 wedge, while the 3057 is a dual-filament T25 wedge. Substituting one for the other would result in an incorrect fit or improper circuit function.
Both bulbs conform to ANSI standards applicable in the United States and Canada, indicating they meet the same regulatory framework but differ in wattage, filament count, and physical size.
The T25 form factor of the 3057 is physically larger than the T15 form factor of the 921, which reflects the different socket types used in the back up light versus the outer back up light positions on the FJ Cruiser.