Volvo V90 Back Up Light Bulb Size

The Volvo V90 back up light requires H21W, 1156, or P21W bulb sizes depending on the specific version of the component. Available data for the bulb sizes covers the range from 1997 to 2021.

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
2021	H21W
2018-2019	H21W
1997-1998	1156

Bulb Specifications

Description	Bulb Size
ECE standard (Europe & worldwide). Single-filament signalling bulb with BAY9s base. 12V, 21W.	H21W
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156

Other Locations

Additional Notes

The H21W is an ECE-standardized single-filament signalling bulb rated at 12V and 21W, fitted with a BAY9s base. It is the bulb type specified for the Volvo V90 across the 2018-2021 model years in the backup light position.
The 1156 is an ANSI-standardized single-filament bulb also rated at 12V and 21W, but fitted with a BA15s bayonet base. It is the bulb type specified for the 1997-1998 V90.
Although both the H21W and the 1156 share identical voltage and wattage ratings of 12V and 21W, they are not interchangeable. The H21W uses a BAY9s base while the 1156 uses a BA15s base, and these two base types are physically incompatible.
The BAY9s base of the H21W is an offset pin bayonet fitting defined under ECE regulations, which are the prevailing standards in Europe and most international markets outside North America.
The BA15s base of the 1156 is a single-contact bayonet fitting defined under ANSI standards, which govern automotive lighting in the United States and Canada.
The regional standardization difference between the two bulb types reflects a broader split in automotive lighting specifications between North American and international markets, with the 1997-1998 V90 following ANSI conventions and the 2018-2021 V90 following ECE conventions.