The Mercedes-Benz ML430 brake light utilizes a P21W bulb size for the rear lighting system. Data for the specific component covers the period from 1999 through 2001.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The P21W is an ECE-standardized single-filament bulb rated at 12 volts and 21 watts, fitted with a BA15s bayonet base. Its single-filament design means it serves one lighting function only, which in this context is braking.
The BA15s bayonet base uses a single contact pin, distinguishing it from the dual-pin BA15d base. This distinction is relevant to fitment, as the two base types are not interchangeable despite their similar physical profile.
The Mercedes-Benz ML430 uses the P21W bulb across both the brake light and the center high mount stop light positions for the 1999-2001 model years.
The shared P21W specification across both lighting positions means the same bulb type serves the standard brake lights and the center high mount stop light, though the two positions remain physically separate installations.
The ECE designation on the P21W indicates compliance with United Nations Economic Commission for Europe regulations, a standard applied broadly outside North America. Its presence in the ML430 specification reflects the European engineering origin of the vehicle.
At 21 watts on a 12-volt system, the P21W draws approximately 1.75 amperes per bulb. This draw is a relevant factor when assessing circuit load, particularly if multiple brake bulbs operate simultaneously.