Mercedes-Benz SLK32 AMG Back Up Light Bulb Size

The Mercedes-Benz SLK32 AMG back up light requires a P21W bulb size for proper installation and function. Data for the specific component covers the range from 2002 to 2004.

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
2002-2004	P21W

Bulb Specifications

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

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Additional Notes

The Mercedes-Benz SLK32 AMG uses the P21W bulb for the back up light across the 2002-2004 model years.
The P21W is an ECE-standardized bulb type, meaning it conforms to European and international automotive lighting regulations rather than SAE standards used in North American specifications.
P21W bulbs operate at 12 volts and consume 21 watts, which is typical for single-filament signalling applications such as reverse lights.
The P21W uses a BA15s bayonet base, where "BA15" refers to the 15mm base width and the lowercase "s" denotes a single contact at the base, distinguishing it from dual-contact variants.
Because the BA15s base is a single-contact design, it is not interchangeable with BA15d bulbs, which carry two contacts and are wired for dual-filament functions.