The Volvo V70 brake component utilizes P21W and 1157 bulb sizes for the rear lighting system. Data for the specific lighting requirements covers the period from 1998 through 2007.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Volvo V70 brake light specification lists three distinct bulb types across its model years: P21W, 1157, and 1156. Each operates on a 12V system, though they differ in filament count, wattage output, and standardization origin.
The P21W is an ECE-standard bulb used in European and worldwide markets. It carries a single filament rated at 21W and uses a BA15s bayonet base. The Volvo V70 uses this bulb for the brake light position across the 2001-2007 model years.
The 1157 is an ANSI-standard bulb common to the US and Canadian markets. Unlike the P21W, it carries a dual filament rated at 21W and 5W, using a BAY15d bayonet base. The V70 uses this bulb for the brake light position in the 1998-2000 model years.
The dual-filament design of the 1157 means it serves two electrical circuits within a single bulb. The higher 21W filament handles the brake function, while the lower 5W filament typically handles a secondary function such as a tail or parking light.
Although the P21W and 1157 share the same 21W brake filament output, they are not interchangeable. The P21W uses a BA15s base with a single offset pin, while the 1157 uses a BAY15d base with two offset pins at different heights. The physical base configurations are incompatible.
The 1156 is an ANSI-standard single-filament bulb rated at 21W with a BA15s bayonet base. The Volvo V70 uses this bulb exclusively for the Center High Mount Stop Light (CHMSL) across the 1998-2006 model years.
The 1156 and P21W share the same BA15s bayonet base type and both carry a single 21W filament. This base compatibility is a known source of fitment confusion, as the two bulbs originate from different standardization systems and may carry slight differences in pin positioning or bulb envelope size.
The CHMSL specification for the V70 does not include a 2007 entry, while the standard brake light specification does not include a 2007 CHMSL entry either. The two sub-parts therefore cover overlapping but non-identical year ranges within the same model.
The shift from the 1157 to the P21W in the standard brake light position occurs between the 2000 and 2001 model years of the Volvo V70. This reflects a change from an ANSI dual-filament bulb to an ECE single-filament bulb, which alters both the base type and the filament configuration for that position.
Because the 1157 is a dual-filament bulb and the P21W is a single-filament bulb, a direct substitution between the two would affect the secondary low-wattage circuit if one was present in the original socket wiring. Fitment decisions for the V70 brake position should account for the model year to confirm which base and filament configuration applies.