Toyota Sienna Trunk Bulb Size

Additional Notes

• The DE3423 is an ANSI-standard festoon bulb operating at 12V with a 41mm length and end-cap contacts. Festoon bulbs seat into spring-loaded holders at both ends rather than using a twist or push-fit socket, which is the defining characteristic of the festoon format.
• The DE3175 shares the same festoon construction and 12V rating as the DE3423 but has a shorter 31mm length. Because the two bulbs differ in physical length, they are not interchangeable despite their identical voltage rating and contact style.
• The Toyota Sienna used the DE3423 for the trunk across the 1999 and 2002-2014 model years, making it the most frequently specified bulb in these trunk fitment records.
• The DE3175 appears in the 1998, 2000, and 2001 model years. Substituting a DE3423 in a holder sized for the DE3175 would result in an improper fit due to the 10mm difference in length between the two festoon bulbs.
• The 2018 Toyota Sienna departs from the festoon format entirely, specifying the 12961, a T10 miniature wedge bulb with a W2.1x9.5d base rated at 12V and 5W. The wedge base is held by friction within a plastic socket rather than by spring-loaded end caps.
• The 12961 designation is a Philips part number rather than an ANSI industry code, which distinguishes it from the DE3423 and DE3175 designations used across the earlier model years in these specifications.
• The T10 wedge format used in the 2018 model year is physically incompatible with the spring-clip festoon holders found in earlier Sienna trunk lamp assemblies, meaning cross-year substitution between these two bulb types is not possible.
• All three bulb types specified across these records operate at 12V, consistent with standard automotive electrical systems.