Subaru Tribeca Back Up Light Bulb Size

The Subaru Tribeca back up light requires a 921 bulb size for proper illumination and function. Data for the specified component covers the range from 2008 through 2014.

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
2008-2014	921

Bulb Specifications

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

Other Locations

Additional Notes

The 921 bulb is the sole back up light bulb size listed for the Subaru Tribeca across all specified model years, covering 2008-2014.
The 921 is a wedge-type bulb, meaning it uses a tapering plastic base that friction-fits directly into a socket without a separate metal connector or bayonet pins.
The T15 designation refers to the bulb's tubular shape, with the numeric portion indicating a width of 15 eighths of an inch, making it a relatively compact single-filament lamp.
The 921 operates at 12 volts and 16 watts, which is consistent with standard automotive electrical systems and typical of reverse light applications.
The 921 carries an ANSI standard designation recognized in both the United States and Canada, indicating a standardized specification for physical form and electrical performance.
Because the 921 is an ANSI-standardized wedge bulb, it is produced by multiple manufacturers, and direct replacements from various brands are generally interchangeable provided they match the T15 wedge base, 12V rating, and 16W output.
LED replacements in the T15 wedge base format are available on the market, though compatibility with the Tribeca's specific socket and any onboard error-detection circuitry is not addressed within these specifications.