Freightliner Sprinter brake bulb sizes include P21/5W and P21W configurations, with the center high mount stop light utilizing a P21W bulb size. The replacement chart covers vehicle production years spanning 2002 to 2021 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 P21/5W bulb is a dual-filament ECE-standard signalling bulb rated at 12V with a 21W main filament and a 5W secondary filament. It uses a BAY15d bayonet base, where the two offset pins prevent incorrect installation by ensuring only one rotational orientation is possible.
The P21W bulb is a single-filament ECE-standard signalling bulb rated at 12V, 21W. It uses a BA15s bayonet base, which has a single contact pin and is not interchangeable with the BAY15d base used by the P21/5W.
The Freightliner Sprinter brake light circuit uses the P21/5W across the majority of model years in the specifications, specifically 2002-2008, 2010-2021, with the 5W filament typically serving as the tail light function and the 21W filament serving as the brake light function within the same bulb.
The P21W single-filament bulb appears in the brake light position for the 2007 and 2009 model years, representing a departure from the dual-filament fitment used in surrounding years. The base type and filament count differ from the P21/5W, making the two types non-interchangeable.
For the 2019-2021 Freightliner Sprinter, the P21/5W specification carries a conditional note indicating it applies specifically to vehicles equipped with halogen capsule headlamps, reflecting a trim-level or configuration dependency for those years.
The center high mount stop light on the Freightliner Sprinter uses the P21W single-filament bulb for the 2002-2006 model years. This application requires only a single filament since the center high mount stop light serves no combined tail light function.
Because the P21W and P21/5W share a similar physical profile but use different bayonet bases (BA15s versus BAY15d), substituting one for the other is not possible without a socket modification, regardless of wattage similarity on the 21W filament.
The ECE designation on both bulb types indicates compliance with United Nations Economic Commission for Europe regulations, a standard widely adopted outside North America, which is consistent with the Sprinter's European origins.