The BMW 2002 front turn signal uses a P21W or P21/5W bulb size, while the rear turn signal requires a P21W bulb size. The replacement chart covers 1966 to 1976 production years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The BMW 2002 turn signal specifications cover model years 1966 through 1976, with two distinct bulb types appearing across the front and rear positions: the P21W and the P21/5W.
The P21W is a single-filament bulb rated at 12V and 21W, built to the ECE standard and fitted with a BA15s bayonet base. It is used exclusively for signalling functions that require only one filament.
The P21/5W is a dual-filament bulb rated at 12V with filaments drawing 21W and 5W respectively, also built to the ECE standard. Its BAY15d bayonet base is offset, meaning it is physically incompatible with the BA15s socket used by the P21W.
Because the BA15s and BAY15d bases are not interchangeable, the P21W and P21/5W cannot be substituted for one another without a socket modification, regardless of their shared 12V operating voltage.
The BMW 2002 front turn signal used the P21/5W for model years 1966-1970, indicating those positions required a dual-filament bulb during that period.
From 1971 onward, the front turn signal specification changed to the single-filament P21W, a configuration that continued through the final listed model year of 1976.
The rear turn signal on the BMW 2002 used the P21W across all listed model years, 1966-1976, without variation.
The front turn signal socket type therefore differs between 1966-1970 models and 1971-1976 models, a distinction relevant to any bulb replacement on earlier vehicles.