Scion tC Back Up Light Bulb Size

The Scion tC back up light utilizes 921 and 7440 bulb sizes for the rear illumination system. Data for the specified vehicle components covers the range from 2005 through 2016.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Back Up Light

Years	US Type	EU Type	Shop
2012-2016	921	W16W	Check Price
2011	7440	W21W	Check Price
2005-2010	921	W16W	Check Price

Outer Back Up Light

If US Type and EU Type show the same value, a direct cross-reference for this bulb is not available or the data is insufficient.

Years	US Type	EU Type	Shop
2012-2016	3057	3057	Check Price
2011	3057 (From 07/2011)	3057	Check Price
2011	7443 (To 07/2011)	W21/5W	Check Price
2010	3057	3057	Check Price
2005-2007	3057	3057	Check Price

Bulb Specifications

Description	Type	Shop
ANSI standard (US & Canada). Wedge bulb (T15). 12V, 16W.	921	Check Price
ANSI standard (US & Canada). Single-filament wedge bulb (T20). 12V, 21W.	7440	Check Price
ANSI standard (US & Canada). Dual-filament wedge bulb (T25). 12V, 27W/7W.	3057	Check Price
ANSI standard (US & Canada). Dual-filament wedge bulb (T20). 12V, 21W/5W.	7443	Check Price

Other Locations

Additional Notes

The 921 bulb is the most frequently specified type across the back up light positions in the Scion tC, appearing in eleven of the twelve model years listed for that position. It is a T15 wedge bulb rated at 12V and 16W, conforming to ANSI standards for the US and Canada markets.
The 3057 bulb dominates the outer back up light position across the listed model years. It is a T25 dual-filament wedge bulb rated at 12V with a 27W main filament and a 7W secondary filament, also conforming to ANSI standards for the US and Canada markets.
The 2011 Scion tC back up light position uses the 7440 bulb rather than the 921 found in all other listed years. The 7440 is a T20 single-filament wedge bulb rated at 12V and 21W, making it a higher-wattage unit than the 921 it replaces in that year.
The 2011 outer back up light position reflects a mid-year bulb change. Units produced through 07/2011 use the 7443, while those produced from 07/2011 onward use the 3057. These two bulbs share the same T20 and T25 wedge base family respectively but differ in wattage ratings, so they are not interchangeable.
The 7443 is a T20 dual-filament wedge bulb rated at 12V with a 21W main filament and a 5W secondary filament. Although it shares a dual-filament configuration with the 3057, the two bulbs differ in base size and wattage, which means substituting one for the other is not supported by the specifications.
The 921 and 7440 bulbs both occupy the same back up light position on the tC but belong to different wedge base sizes, T15 and T20 respectively. This size difference means the two types are not interchangeable despite both being single-filament bulbs operating at 12V.
All four bulb types listed across these specifications conform to ANSI standards applicable to the US and Canada markets, and all operate on a 12V electrical system consistent with standard automotive applications.
The outer back up light position carries no entries for the 2008 and 2009 model years in the provided specifications, while the standard back up light position carries entries for all twelve model years from 2005 through 2016.