Freightliner Cascadia Back Up Light Bulb Size

The Freightliner Cascadia back up light uses 1156 and P21W bulb sizes according to the provided technical data. Information for the specified components covers the time range from 2008 through 2017.

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	US Type	EU Type	Shop
2008-2022	1156	P21W	Check Price

Bulb Specifications

Description	Type	Shop
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156	Check Price
ECE standard (Europe & worldwide). Single-filament signalling bulb with BA15s bayonet base. 12V, 21W.	P21W	Check Price

Other Locations

Additional Notes

The 1156 is the sole back up light bulb size listed for the Freightliner Cascadia across all model years in the specifications, covering 2008-2022.
The 1156 is a single-filament bulb, meaning it serves one lighting function only, which is consistent with its dedicated role as a back up light.
It operates on a 12-volt electrical system and draws 21 watts, placing it in the standard incandescent output range for automotive reverse lighting applications.
The 1156 uses a BA15s bayonet base, a single-contact mount where the "s" denotes a single pin, distinguishing it from the dual-contact BA15d base used in two-filament bulbs such as the 1157.
The 1156 conforms to ANSI standards recognized in both the United States and Canada, indicating a standardized specification rather than a proprietary or region-specific design.
Because the 1156 is single-filament and the visually similar 1157 is dual-filament with a different base pin configuration, the two are not interchangeable despite sharing the same BA15 base family.