Audi S4 Stepwell Bulb Size

The Audi S4 stepwell light requires a 12961 bulb size for proper installation and function within the interior lighting system. Available data for the specific component covers the range from 2000 to 2015.

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
2010-2015	12961 (Door Warning Light AND Entry Light)
2007-2009	12961 (Door Warning Light AND Footwell Light AND Entry Light)
2000	12961

Bulb Specifications

Description	Bulb Size
Philips part number. Miniature wedge bulb (T10) with W2.1x9.5d base. 12V, 5W.	12961

Other Locations

Additional Notes

The Audi S4 uses the 12961 bulb across all stepwell lighting positions listed in the specifications, spanning model years 2000 and 2007-2015.
The 12961 is a Philips part number designating a T10 miniature wedge bulb with a W2.1x9.5d base, rated at 12 volts and 5 watts.
The T10 form factor is a small cylindrical wedge-type bulb commonly used in low-intensity interior lighting applications such as courtesy, footwell, and door-mounted positions.
The W2.1x9.5d base designation describes a wedge-style connection where the bulb pins directly into a socket without a separate metal cap, a standard configuration for 5W interior bulbs.
For the 2007-2009 Audi S4, the 12961 bulb serves three distinct stepwell functions: the Door Warning Light, the Footwell Light, and the Entry Light, all sharing the same bulb type.
For the 2010-2015 Audi S4, the 12961 bulb covers two stepwell functions: the Door Warning Light and the Entry Light.
Because multiple lighting positions across the Audi S4 share the 12961 specification, a single bulb type is interchangeable among all listed stepwell sockets within the same model year.
The 5W power rating of the 12961 places it in the low-wattage category typical of interior ambient and safety lighting, where heat output and current draw are kept minimal.