Scion xA front side marker bulb uses 194 size while rear side marker bulb uses 7443 size. Replacement chart covers 2004 to 2006 vehicle production years with bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Scion xA uses the 194 bulb for the front side marker position across the 2004-2006 model years, while the rear side marker position uses the 7443 bulb across the same span.
The 194 is a T10 miniature wedge bulb rated at 12V and 3.78W, conforming to ANSI standards recognized in both the United States and Canada.
The 7443 is a T20 dual-filament wedge bulb rated at 12V with a 21W main filament and a 5W secondary filament, also conforming to ANSI standards recognized in both the United States and Canada.
The dual-filament construction of the 7443 means it serves two independent electrical circuits within a single bulb housing, which is a distinct characteristic from the single-filament 194 used at the front.
The T10 and T20 designations refer to the outer width of the wedge base, with T20 being physically larger than T10, making the front and rear side marker bulbs non-interchangeable by form factor alone.
The wattage difference between the two bulbs is substantial, with the 7443 drawing up to 21W on its primary filament compared to the 3.78W draw of the 194, reflecting their different functional roles.
Because both bulb types use wedge-style bases rather than bayonet or screw bases, installation requires no rotation to lock the bulb in place.