Mercedes-Benz 200D Back Up Light Bulb Size

The Mercedes-Benz 200D back up light utilizes a P21W bulb size for the specific lighting component located at the rear of the vehicle. Available data for the bulb specifications covers the period from 1968 through 1973.

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
1968-1973	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 P21W is the sole back up light bulb size specified for the Mercedes-Benz 200D across the 1968-1973 model years.
The P21W is an ECE-standard single-filament bulb rated at 12 volts and 21 watts, designed for signalling applications such as back up lights.
The P21W uses a BA15s bayonet base, which is a single-contact bayonet fitting with a 15mm collar width.
The BA15s base designation indicates a single-contact configuration, distinguishing it from the dual-contact BA15d variant, which is not interchangeable with the P21W.
The ECE standard governing the P21W reflects a specification recognized across European and worldwide markets, consistent with the Mercedes-Benz 200D as a European-market vehicle.
As a single-filament bulb, the P21W serves one dedicated function per housing, with no secondary filament for combined stop or tail light duties.