Scion xB front inner and rear turn signal bulbs utilize 1157NA, 1034NA, and 7440NA bulb sizes depending on location and model variation. The replacement chart covers 2004 through 2015 production years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 7440NA and 7440 bulbs are both single-filament T20 wedge-base types rated at 12V and 21W. The NA designation indicates natural amber glass, whereas the standard 7440 uses clear glass. Both share the same wattage and base configuration.
The 1157NA and 1034NA bulbs are dual-filament types with a BAY15d bayonet base, rated at 12V with a 21W/5W filament arrangement. The dual-filament design allows one bulb to serve both a running light and a turn signal function simultaneously.
The "NA" suffix across all four bulb types denotes natural amber glass, which produces an amber signal color through the glass itself rather than through an amber-tinted lens or housing.
For the Scion xB front turn signal, the 2008 model year uses the 1034NA, while the 2004-2006 and 2009-2010 model years use the 1157NA. The 1034NA is noted as a variant of the 1157, though the two are not listed as interchangeable within these specifications.
The rear turn signal position transitions from the 7440NA in 2004-2006 to the standard 7440 in 2008-2010, then returns to the 7440NA for 2011-2015. Since both share the same T20 wedge base and 21W rating, the distinction lies solely in glass tint.
The front turn signal position for 2011-2015 uses the 7440NA, representing a shift from the dual-filament BAY15d bulbs used in earlier model years to a single-filament wedge-base type.
The front inner turn signal position, present only in 2004-2006, uses the 1034NA in 2004 and the 1157NA in 2005-2006. This position does not appear in later model years within these specifications.