The Mercedes-Benz S430 front turn signal requires a 2357NA bulb size, while the rear turn signal uses either 12496 or PY21W bulb sizes. The replacement chart covers 2000 to 2006 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 Mercedes-Benz S430 front turn signal uses the 2357NA bulb across all model years from 2000-2006 without variation.
The 2357NA is an ANSI-standard dual-filament bulb rated at 12V with a high filament draw of 26.9W and a low filament draw of 8W, fitted with a BAY15d bayonet base and natural amber glass.
The natural amber glass of the 2357NA produces the required amber signal color directly from the bulb itself, rather than relying on a colored lens housing.
The rear turn signal position on the S430 alternates between two distinct bulb types depending on the model year, with 2000, 2001, 2003, and 2005 using the PY21W and 2002, 2004, and 2006 using the 12496.
The PY21W is an ECE-standard single-filament amber bulb rated at 21W with a BAU15s bayonet base, a standard common in European and international vehicle markets.
The 12496 is a Philips/Osram part number designation for a 12V halogen bulb intended for specialty applications, and it is not an ANSI or ECE standard classification.
The BAY15d base of the 2357NA and the BAU15s base of the PY21W are physically distinct and not interchangeable, as the BAU15s features offset pins at 150 degrees while the BAY15d uses parallel offset pins.
Because the front and rear positions use different base types across the S430 model range, a bulb sourced for one position is not a direct fit for the other.
The 2357NA and PY21W also differ in filament count, with the 2357NA carrying dual filaments and the PY21W carrying a single filament, which affects their respective circuit compatibility.
Owners of the S430 (Mercedes-Benz) should note that the rear turn signal bulb type is not uniform across the full 2000-2006 production span, making the specific model year a necessary reference before sourcing a replacement.