Mercedes-Benz C220 front turn signal bulbs utilize a P21/5W size while rear turn signal bulbs require a P21W size. The replacement chart covers 1994 through 1996 production years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Mercedes-Benz C220 uses two distinct turn signal bulb types across its front and rear positions: the P21/5W for the front and the P21W for the rear, both conforming to ECE standards recognized in Europe and worldwide.
Both bulb types operate on a 12-volt electrical system, which is standard for passenger vehicles of this era.
The P21/5W is a dual-filament bulb, meaning it serves two lighting functions within a single unit. Its 21-watt filament handles the turn signal function, while the 5-watt filament serves a secondary purpose such as a parking or position light.
The P21W is a single-filament bulb rated at 21 watts, dedicated solely to the rear turn signal function on the C220.
The P21/5W uses a BAY15d bayonet base. This base type features two offset pins at different heights, a design that prevents incorrect installation by ensuring the bulb can only be seated in one orientation.
The P21W uses a BA15s bayonet base, which is a single-contact base with two pins at the same height. This base is not interchangeable with the BAY15d used by the P21/5W, despite the similar physical size of the two bulbs.
Because the BAY15d and BA15s bases are mechanically different, substituting a P21W in place of a P21/5W front position, or vice versa, is not possible without a socket adapter.
The front turn signal specification for the Mercedes-Benz C220 remains P21/5W across the 1994-1996 model years, and the rear turn signal specification remains P21W across the same period.