Volvo S40 front inner turn signal bulbs utilize 3457NA or 3357NA size, while front and rear turn signal bulbs require PY21W or 12496 size bulbs. The replacement chart covers vehicle production years spanning 2000 to 2011 with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 3457NA and 3357NA bulbs follow the ANSI standard used in the United States and Canada, while the PY21W follows the ECE standard used in Europe and worldwide markets. The Volvo S40 specifications include both standards across its model years, reflecting regional market variations in the vehicle's production.
The PY21W bulb uses a BAU15s bayonet base, which is an offset-pin base. This offset pin design prevents the bulb from being seated in a socket intended for a standard BA15s base, making cross-installation with non-amber bayonet bulbs physically restricted by design.
The 3457NA is a dual-filament bulb rated at 27W/7W, while the 3357NA is a single-filament bulb rated at 27W. Although both share the T25 wedge form factor and natural amber glass, their filament configurations differ, and they are not functionally interchangeable in sockets that rely on the secondary 7W filament.
The 3457NA and 3357NA bulbs both feature natural amber glass rather than a clear envelope with an amber-coated filament. This construction method produces the amber output required for turn signal applications under ANSI standards.
For the Volvo S40, the front inner turn signal position uses ANSI-standard bulbs exclusively across the 2000-2004 model years, with the 3457NA specified for 2000-2001 and 2003-2004, and the 3357NA specified for 2002.
The 2009 Volvo S40 front turn signal has two separate bulb specifications depending on headlamp type. Vehicles equipped with halogen capsule headlamps use the 12496, while vehicles equipped with HID headlamps use the PY21W. This represents a within-year fitment split tied directly to the headlamp system installed on the vehicle.
The 12496 is a Philips/Osram part number rather than an ANSI or ECE standardized designation. It is rated at 12V and classified as a specialty halogen application bulb, meaning it does not carry a universal cross-reference code in the way that 3457NA or PY21W bulbs do.
The rear turn signal position on the Volvo S40 alternates between the PY21W and 12496 across multiple model years, with no single bulb type used consistently throughout the full production range covered by the specifications. This means the rear turn signal bulb type cannot be assumed based on vehicle generation alone without consulting the specific model year.
The PY21W is rated at 21W, while the 3457NA operates its primary filament at 27W. These wattage differences are relevant to turn signal flasher relay calibration, as some relay units are sensitive to load and may produce incorrect flash rates if a bulb of a significantly different wattage is substituted.
The front turn signal position for the 2010 Volvo S40 uses the 12496, while the 2011 model year uses the PY21W. Despite being consecutive years, the two positions require different bulb types, and the rear turn signal follows the inverse pattern, with the 2010 using the 12496 and the 2011 using the PY21W as well.