BMW Motorcycle R1150GS front and rear turn signal bulbs use PY21W, P21W, or 12496 bulb sizes. The replacement chart covers 1999-2005 production 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 BMW Motorcycle R1150GS turn signal specifications cover model years 1999-2005 for both front and rear positions, with each year listing separate bulb sizes depending on whether the lens is clear or non-clear.
P21W is the bulb specified across all years and both positions when the lens is not clear. It is an ECE-standard single-filament signalling bulb rated at 12V and 21W, fitted with a BA15s bayonet base.
PY21W appears as the predominant clear-lens specification across most years for both front and rear positions. It is an ECE-standard single-filament amber bulb rated at 12V and 21W, fitted with a BAU15s bayonet base.
Although PY21W and P21W share the same 12V and 21W ratings, their bayonet bases differ. PY21W uses a BAU15s offset-pin base, while P21W uses a BA15s straight-pin base, making the two types physically non-interchangeable.
The amber color in PY21W is built into the bulb itself, which is why it is paired with clear lenses. P21W produces white light and relies on a colored lens to produce the amber signal output required by ECE regulations.
The 12496 is a Philips/Osram part number designating a 12V halogen bulb for specialty applications. It appears in the clear-lens front turn signal position for 2002-2004 and in the clear-lens rear turn signal position for 1999 and 2002.
In the 2003 front turn signal position, both 12496 and PY21W are listed for clear-lens fitment, indicating that either bulb type was applicable to that configuration in that year.
The rear turn signal for the 2004 R1150GS specifies PY21W for the clear-lens variant, whereas the front turn signal for the same year specifies 12496 for the clear-lens variant, meaning front and rear clear-lens requirements differ for that model year.