The Scion FR-S back up light requires a 921 bulb size for proper installation and function within the rear lighting assembly. Available data covers the specific range from 2013 to 2016.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 921 bulb is the sole bulb size specified for the Scion FR-S backup light positions across the 2013-2016 model years.
The 921 bulb follows the ANSI standard recognized in the United States and Canada, meaning it conforms to a defined set of electrical and physical specifications shared across compliant manufacturers.
The 921 uses a wedge-style base, designated T15, which refers to a tubular bulb body approximately 15 eighths of an inch wide. The wedge base has no metal pins and is held in place by tension from the socket itself.
The 921 operates at 12 volts and 16 watts, which are standard values for automotive reverse light applications powered by a vehicle's 12-volt electrical system.
The Outer Back Up Light on the 2016 Scion FR-S carries a production cutoff notation of "To 06/2016," indicating the 921 bulb size applies only to vehicles produced through June of that year.
The T15 wedge base format of the 921 is shared with several other bulb numbers in the same family, such as the 912 and 916. Those alternatives differ in wattage, which affects brightness and electrical load, so substitution requires attention to the rated wattage of the replacement.