Volvo XC90 Turn Signal Bulb Size

Additional Notes

• The H21W is the most frequently specified bulb across the Volvo XC90 turn signal positions. It follows the ECE standard used in Europe and worldwide markets, operates at 12V with a 21W output, and uses a BAY9s base. This single-filament signalling bulb covers the front inner turn signal for all listed model years from 2003-2012, as well as the front turn signal from 2003-2014.
• The BAY9s base on the H21W is an offset bayonet fitting, which is physically distinct from other common bayonet bases. This means it is not interchangeable with bulbs using different base types, even when voltage and wattage ratings are otherwise similar.
• The PY21W shares the same 12V, 21W rating as the H21W but uses a BAU15s bayonet base rather than a BAY9s. The angular offset of the BAU15s base is different from standard BA15s fittings, making it a keyed fitment that prevents installation of non-amber bulbs in amber-designated sockets. It appears in the rear turn signal position across several XC90 model years.
• The 12496 is a Philips/Osram part number designating a halogen bulb for specialty applications, rated at 12V. It is specified for the Volvo XC90 rear turn signal in 2003, 2006-2007, 2011-2012, and 2014.
• The rear turn signal position on the Volvo XC90 alternates between the PY21W and the 12496 across different model years, meaning the two bulbs are not universally interchangeable for this vehicle despite both serving the same function.
• The PY24WNA follows the ANSI standard used in the US and Canadian markets. It is an amber variant of the ECE PY24W, rated at 12V and 24W, and uses a PGU20-4 base. It is specified for the Volvo XC90 front turn signal from 2016-2019 on vehicles equipped with halogen capsule headlamps.
• The 2020 front turn signal specification transitions from the PY24WNA to the 12174NA, with both years retaining the halogen capsule headlamp condition. The 12174NA is an OEM part number for a natural amber glass bulb rated at 12V, and it also covers the 2021 model year without a stated headlamp condition qualifier.
• The PGU20-4 base used by the PY24WNA is a wedge-type fitting specific to higher-wattage front turn signal applications. It is not compatible with the BAU15s or BAY9s bayonet bases found on the PY21W and H21W respectively.
• The front inner turn signal position on the Volvo XC90 uses the H21W exclusively across all listed years from 2003-2012, while the front outer turn signal position for the same years also uses the H21W, indicating both positions shared the same bulb type during that generation.
• The natural amber glass construction of the 12174NA means the bulb itself produces amber-colored light without relying on a tinted lens or housing. This is a characteristic it shares functionally with the PY24WNA and PY21W, both of which are also designated as amber-output bulbs.