The Volvo XC90 side marker utilizes 7443 and 12961 bulb sizes for the lighting components. Data for the specified vehicle covers the period from 2007 through 2016.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 12961 is the most widely used bulb across the Volvo XC90 side marker specifications. It is a Philips part number designating a T10 miniature wedge bulb with a W2.1x9.5d base, rated at 12V and 5W.
The front side marker of the Volvo XC90 uses the 12961 bulb across all listed model years from 2003-2014, with no variation in bulb type throughout that entire span.
The rear side marker follows the same 12961 fitment for 2004-2012, making the bulb interchangeable between front and rear positions on those model years.
The 2003 rear side marker is the only position in the specifications that calls for a P21/4W bulb. This is an ECE-standard dual-filament bulb with a BAZ15d bayonet base, rated at 12V with filaments at 21W and 4W, and it is not interchangeable with the 12961 used in all other listed positions.
The 2016 rear side marker uses a 7443 bulb, an ANSI-standard T20 dual-filament wedge type rated at 12V with filaments at 21W and 5W. This bulb type is physically and electrically distinct from the 12961 and cannot serve as a substitute for it.
The rear side marker entries for 2013 and 2014 carry chassis range qualifiers, specifying fitment from chassis 628377 to chassis 518050. This indicates that bulb size selection for those years is dependent on the specific chassis number of the vehicle rather than the model year alone.
The W2.1x9.5d base of the 12961 is a wedge-type connection, meaning the bulb is held in place by tension from the socket rather than a locking bayonet mechanism. This contrasts with the BAZ15d bayonet base of the P21/4W, which requires a twist-lock installation.
The P21/4W and 7443 are both dual-filament bulbs, while the 12961 is a single-filament type. A dual-filament bulb serves two lighting functions from one unit, whereas the 12961 serves only one.