The Toyota Yaris iA brake light requires a 7443 bulb size for proper installation and function. Data for the specified lighting component covers the range from 2017 to 2018.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Toyota Yaris iA uses the 7443 bulb for its brake light application across the 2017-2018 model years. This bulb follows the ANSI standard recognized in both the United States and Canada.
The 7443 is a dual-filament wedge bulb built on the T20 form factor, operating at 12 volts with a wattage rating of 21W on the high filament and 5W on the low filament. The dual-filament design allows a single bulb to serve both brake and tail light functions within the same housing.
The outer brake position on the 2017-2018 Yaris iA takes a separate and distinct bulb, the 12961, rather than sharing the 7443 fitment used in the primary brake position. These two positions are not interchangeable.
The 12961 is a miniature wedge bulb built on the T10 form factor, rated at 12 volts and 5W. It uses a W2.1x9.5d base, which is the standard wedge base type for T10 bulbs.
Because the 7443 and 12961 differ in physical size, base type, wattage, and filament count, substituting one for the other is not possible. The T20 body of the 7443 is physically larger than the T10 body of the 12961.
The 12961 designation is a Philips part number rather than an ANSI industry-wide code, which means cross-referencing with equivalent bulbs from other manufacturers requires matching the T10 form factor and W2.1x9.5d base specification rather than the part number alone.