Chevrolet Volt Back Up Light Bulb Size

The Chevrolet Volt back up light utilizes bulb sizes 7440, 2458, and 3157 for various lighting assemblies. Available information covers a span of time starting in 2011 and ending in 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
2016-2019	7440
2011-2015	3157

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament wedge bulb (T20). 12V, 21W.	7440
ANSI standard (US & Canada). Dual-filament wedge bulb (T25). 12V, 27W/7W.	3157

Other Locations

Additional Notes

The Chevrolet Volt backup light specifications cover model years 2011 through 2019 and reference two distinct bulb sizes across that span.
The 7440 is a single-filament T20 wedge bulb rated at 12V and 21W, conforming to the ANSI standard used in the United States and Canada.
The 3157 is a dual-filament T25 wedge bulb rated at 12V with a dual-wattage output of 27W and 7W, also conforming to the ANSI standard used in the United States and Canada.
The dual-filament design of the 3157 means the bulb carries two separate circuits within a single housing, each operating at a different wattage.
The Chevrolet Volt (2016-2019) uses the 7440 bulb for the backup light position.
The 2011-2015 Volt uses the 3157 bulb for the same position.
The two bulb types are not interchangeable. The T20 and T25 wedge bases differ in physical size, and the socket configurations are not compatible with one another.
The wattage difference between the 7440 at 21W and the 3157 at 27W reflects a meaningful difference in power draw, which is relevant when considering socket and wiring compatibility.
A bulb change occurred between the 2015 and 2016 model years, coinciding with the transition from the first-generation Volt to the second-generation platform.