The Mercedes-Benz ML55 AMG tail light requires a P21/4W bulb size for the rear lighting assembly. Data for the specific component covers the range from 2000 to 2003.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Mercedes-Benz ML55 AMG uses the P21/4W bulb across all listed model years for the outer tail light position, spanning 2000-2003.
The P21/4W is an ECE-standard bulb, meaning it conforms to European and internationally recognized regulations for automotive lighting.
P21/4W is a dual-filament bulb, which allows it to serve two separate lighting functions within a single housing, typically combining a brighter stop function with a dimmer running light function.
The bulb operates at 12 volts, consistent with the standard electrical system voltage found in passenger vehicles of this era.
The two filaments in the P21/4W are rated at 21 watts and 4 watts respectively, with the higher-wattage filament designated for the stop signal and the lower-wattage filament for the tail light function.
The P21/4W uses a BAZ15d bayonet base, which is an offset twin-contact base. The asymmetric pin placement of the BAZ15d prevents incorrect installation, as the bulb can only be seated in one orientation.
The BAZ15d base is specific to dual-filament bulbs and is not interchangeable with the single-contact BA15s base or the symmetrical twin-contact BAY15d base, making substitution with physically similar bulbs a fitment concern.