The Toyota Corolla back up light utilizes bulb sizes 921, P21W, and 1156 for various lighting assemblies. Available information spans a range from 1972 through 2024 for the specified vehicle components.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 921 bulb is a T15 wedge-type, rated at 12V and 16W under the ANSI standard applicable in the US and Canada. The Toyota Corolla uses this bulb as the back up light across model years 1998-2024, making it the most consistently specified bulb in these fitment records.
The 1156 bulb uses a BA15s single-contact bayonet base and operates at 12V and 21W. It is a single-filament type, meaning it serves one lighting function per socket. The Corolla back up light relied on this bulb from 1972-1997, as well as in select outer back up light positions through 1997.
The 3057 bulb is a dual-filament T25 wedge type rated at 12V with two wattage levels, 27W and 7W, conforming to the ANSI standard for the US and Canadian markets. In the Toyota Corolla, it appears exclusively in the inner back up light position for model years 2009-2015.
The inner back up light position on the Toyota Corolla shows a bulb change between the 2015 and 2016 model years, shifting from the 3057 dual-filament type to the 921 single-filament wedge. These two bulb types are not interchangeable due to differences in base design and filament configuration.
The 921 and 3057 bulbs both use wedge-style bases but are not the same size, as the 3057 is a T25 and the 921 is a T15. Substituting one for the other in the inner back up light socket is not supported by these specifications.
The 1156 bayonet-base bulb and the 921 wedge bulb require different socket types and are physically incompatible. The back up light specification for the Toyota Corolla transitions from the 1156 to the 921 between the 1997 and 1998 model years.
The 1987 Toyota Corolla back up light specification for the 1156 bulb carries a notation indicating it applies to vehicles equipped with halogen capsule headlamps, distinguishing that fitment from other years in the 1156 range.
The outer back up light on the Toyota Corolla uses the 1156 bulb for the 1995-1997 model years, with the 1995 entry further qualified as applying only to production through August 1995, indicating a mid-year specification change for that position.