Mercedes-Benz C230 Back Up Light Bulb Size

The Mercedes-Benz C230 back up light utilizes a P21W bulb size for illumination across all recorded vehicle versions. Available data covers a specific time range starting from 1997 and ending in 2007.

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
2002-2007	P21W
1997-2000	P21W

Bulb Specifications

Description	Bulb Size
ECE standard (Europe & worldwide). Single-filament signalling bulb with BA15s bayonet base. 12V, 21W.	P21W

Other Locations

Additional Notes

The Mercedes-Benz C230 uses the P21W bulb size across all listed model years from 1997 to 2007, with no variation in specification throughout that span.
The P21W is an ECE-standardized bulb type, meaning its specifications conform to European and internationally recognized automotive lighting regulations rather than SAE standards used primarily in North America.
P21W bulbs operate on a 12-volt electrical system and draw 21 watts, which is a typical power rating for single-filament signalling applications such as backup lights.
The P21W uses a BA15s bayonet base, where "BA" denotes a bayonet-style cap, "15" refers to the 15mm base width, and the lowercase "s" indicates a single-contact configuration.
Because the P21W is a single-filament bulb, it serves one dedicated function per housing, as opposed to dual-filament types that combine two functions such as braking and running light within a single bulb.
The BA15s bayonet mount is not interchangeable with the BA15d base, which carries two contacts. Substituting a BA15d bulb in a BA15s socket is not compatible due to the differing contact configurations.
The P21W designation is part of a broader ECE bulb family, and while other members of that family may share a similar physical form, wattage and base type differences make cross-substitution inadvisable without confirming an exact specification match.