The Toyota Mirai dome light requires a DE3175 bulb size for proper installation and function within the interior lighting housing. Data for the specified component covers the range from 2016 to 2019.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The DE3175 is an ANSI-standard festoon bulb rated at 12V, measuring 31mm in length with end-cap contacts. It is the dominant bulb type across the Toyota Mirai dome light specifications, appearing in both the general dome light position for 2016-2019 and the front dome light center position for the 2017 and 2019 model years.
Festoon bulbs make contact at both ends of the housing rather than through a base socket, which is a defining characteristic of the DE3175 format. This contact style is common in interior dome and map light applications across many vehicle lines.
The 12961 is a Philips part number designating a miniature wedge bulb in the T10 form factor, using a W2.1x9.5d base. It is rated at 12V and 5W. This bulb type seats into a wedge socket rather than spanning between two end contacts, making it physically and electrically incompatible with a festoon socket.
The Toyota Mirai (2018) front dome light center position uses the 12961 wedge bulb, while the same position on the 2017 and 2019 models uses the DE3175 festoon bulb. These two bulb types are not interchangeable due to their different base designs.
The general dome light position across all four model years (2016-2019) consistently specifies the DE3175, indicating that this festoon format is the standard fitment for that location regardless of the front dome light center variation seen in 2018.
The DE3175 designation is recognized under ANSI standards and is applicable in both the United States and Canada, reflecting a standardized part number used across multiple manufacturers rather than a proprietary designation.