Buick LaCrosse Back Up Light Bulb Size

The Buick LaCrosse back up light utilizes a 921 bulb size for illumination across all listed vehicle configurations. Available data covers a continuous span from 2005 through 2019.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Size
2005-2019	921

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Wedge bulb (T15). 12V, 16W.	921

Other Locations

Additional Notes

The Buick LaCrosse uses the 921 bulb size for the back up light across all model years from 2005-2019.
The 921 is an ANSI-standardized bulb type, meaning its specifications are governed by a recognized North American standard applicable in both the United States and Canada.
The 921 bulb belongs to the T15 wedge family, a designation that refers to its tubular glass envelope and wedge-style base, which connects directly into a socket without a separate metal base or pins.
The 921 operates at 12 volts and draws 16 watts, figures consistent with standard automotive electrical systems and typical reverse light output requirements.
The wedge base design of the 921 means fitment depends on socket compatibility with that specific base type, and bulbs with different base styles are not interchangeable even if their voltage and wattage ratings are similar.