Toyota Sienna Stepwell Bulb Size

Additional Notes

• The Toyota Sienna stepwell uses three distinct bulb types across its model years: the 168, the 194, and the DE3423, each with different electrical and physical characteristics.
• The 194 bulb is the most frequently specified type in these records, appearing across the 1998-2005 and 2008-2009 model years. It is an ANSI-standard miniature wedge bulb of the T10 form factor, rated at 12V and 3.78W.
• The 168 bulb shares the same T10 wedge form factor as the 194 but draws slightly more power at 4.9W versus 3.78W. It is specified for the 2011-2014 and 2018 model years.
• Because the 168 and 194 are both T10 wedge bulbs, they are physically interchangeable in the socket, though their wattage ratings differ. Substituting one for the other may affect circuit load and light output.
• The DE3423 is a festoon-type bulb with a 41mm length and end-cap contacts, making it physically incompatible with the wedge sockets used by the 168 and 194. It is specified for the Toyota Sienna in the 2006, 2007, and 2010 model years.
• All three bulb types are ANSI-standard parts rated for 12V operation, consistent with standard automotive electrical systems in the United States and Canada.
• The stepwell position on the Sienna does not use a single bulb type across all recorded years, meaning direct year-to-year part substitution is not always valid without confirming the specific model year requirement.