Scion iQ Side Marker Bulb Size

The Scion iQ rear side marker bulb uses a 7443 size bulb for this model. The replacement chart covers vehicle production years spanning 2012 to 2015.

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

Rear Side Marker

Years	US Type	EU Type	Shop
2012-2015	7443	W21/5W	Check Price

Description	Type	Shop
ANSI standard (US & Canada). Dual-filament wedge bulb (T20). 12V, 21W/5W.	7443	Check Price

The Scion iQ uses the 7443 bulb for the rear side marker position across all listed model years, spanning 2012-2015.
The 7443 is a dual-filament wedge bulb built to the T20 form factor, operating at 12 volts with a wattage rating of 21W on the primary filament and 5W on the secondary filament.
The dual-filament design of the 7443 allows it to serve two distinct brightness levels within a single housing, which is why it is commonly used in positions that require both a running light and a brighter signal or brake function.
The 7443 conforms to ANSI standards as recognized in the United States and Canada, meaning it follows a defined specification for base type, voltage, and wattage rather than being a proprietary or regional-only part.
The T20 wedge base of the 7443 is not compatible with single-filament T20 bulbs such as the 7440, despite sharing the same physical socket family. Substituting a single-filament variant would result in the loss of one lighting function.