The Mercedes-Benz ML430 front inner turn signal requires a 1157NA bulb size, front outer turn signal uses a 12961 bulb size, front turn signal uses a 2357NA bulb size, and rear turn signal uses a 12496 or PY21W bulb size. The replacement chart covers 1999 to 2001 model 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 1157NA and 2357NA bulbs share the same BAY15d bayonet base and both carry natural amber glass, making them physically similar in mounting style. However, the 2357NA operates at a higher wattage of 26.9W/5W compared to the 1157NA at 21W/5W, and the two are not interchangeable despite the shared base type.
The NA suffix on both the 1157NA and 2357NA designates natural amber glass, meaning the amber color is produced by the glass itself rather than by an amber-tinted housing or lens. This is relevant to turn signal output color compliance.
The Mercedes-Benz ML430 uses the 2357NA for the front turn signal position across all three model years (1999-2001), while the front inner turn signal position uses the lower-wattage 1157NA across the same span.
The front outer turn signal on the ML430 uses the 12961, a Philips-numbered miniature wedge bulb with a W2.1x9.5d base operating at 12V and 5W. This wedge base format is physically distinct from the BAY15d bayonet base used in the 1157NA and 2357NA, and the bulbs are not cross-compatible.
The rear turn signal specification for the 2000 model year lists the PY21W, an ECE-standard single-filament amber bulb with a BAU15s bayonet base. The BAU15s base is offset, distinguishing it from the straight-pin BAY15d base used on other bulbs in this specification set.
The 1999 and 2001 model years specify the 12496 for the rear turn signal, while the 2000 model year specifies the PY21W. These two bulbs use different base types and are not interchangeable with each other.
The PY21W follows ECE regulations, which are the prevailing standards in Europe and most international markets. Its presence in the 2000 ML430 rear turn signal position reflects a regionally sourced or specified component rather than the ANSI-standard parts used elsewhere in the specification set.
The 12496 is identified under Philips and Osram part numbering as a specialty halogen bulb rated at 12V. Its classification as a specialty application bulb indicates it is not part of a broadly standardized series like the ANSI or ECE families represented by other bulbs in this set.
Across all three model years, the ML430 uses dual-filament bulbs in both the front inner and front turn signal positions. Dual-filament bulbs serve two independent circuits, typically combining turn signal and parking or daytime running light functions within a single housing.
The 12961 wedge bulb operates at only 5W, the lowest wattage among all bulbs listed in this specification set. Its single-filament, low-wattage profile is consistent with a supplementary or marker-type function rather than a primary turn signal role.