The Toyota Tacoma back up light utilizes bulb sizes 921, 1156, and P21W depending on the specific vehicle configuration. Available information covers the range from 1995 through 2023.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Toyota Tacoma uses two bulb types across its back up light specifications: the 921 and the 1156, both of which conform to ANSI standards for the US and Canadian markets.
The 921 is a T15 wedge-base bulb rated at 12 volts and 16 watts. Its wedge-style base requires no locking pins, as the base itself is held in place by the socket housing.
The 1156 is a single-filament bulb with a BA15s bayonet base, rated at 12 volts and 21 watts. The BA15s designation indicates a single-contact bayonet fitting with a 15mm base width.
The 921 and 1156 are not interchangeable. Beyond their different base types, the 1156 draws 21 watts versus the 921's 16 watts, and the socket designs are physically incompatible.
For the back up light position, the Toyota Tacoma used the 1156 from 1995-2000 and transitioned to the 921 from 2001 onward through the 2023 model year.
For the outer back up light position, the 2001 model year specifies the 921 only from September 2000 onward, and the 2005 model year specifies the 921 only from September 2004 onward, indicating mid-cycle production changes within those model years.
The outer back up light on the 1995 model year carries a production date qualifier of January 1995, indicating the specification applies from that point within the model year's production run.