BMW 2002 Back Up Light Bulb Size

The BMW 2002 back up light requires a P21W bulb size for proper installation and function within the rear lighting assembly. Available data covers the time range from 1966 to 1976.

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
1966-1976	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 BMW 2002 uses the P21W bulb for the back up light across all listed model years, spanning 1966-1976.
The P21W is an ECE-standard bulb, meaning it conforms to the Economic Commission for Europe's regulations, which govern lighting equipment used in European and international automotive markets.
P21W bulbs operate on a 12-volt electrical system and draw 21 watts, which is consistent with standard incandescent signalling applications.
The P21W is a single-filament bulb, meaning it serves one lighting function only, as opposed to dual-filament types that combine two functions such as braking and running light in a single unit.
The P21W uses a BA15s bayonet base, where "BA15" refers to the 15mm pin spacing of the bayonet cap and "s" denotes a single contact at the base, distinguishing it from the BA15d, which carries two contacts for dual-filament use.
The BA15s base type is not interchangeable with BA15d sockets, as the contact configuration differs between the two, and substituting one for the other is not supported by the specifications for this vehicle.