Oldsmobile LSS Back Up Light Bulb Size

Additional Notes

• The Oldsmobile LSS back up light specifications span four model years, 1996-1999, with a different bulb size specified for each year.
• All four bulb types listed across these model years conform to ANSI standards recognized in both the United States and Canada.
• All four bulbs operate on a 12-volt electrical system, which is standard for automotive applications of this era.
• The 1999 Oldsmobile LSS uses the 3156, a single-filament wedge bulb in the T25 form factor rated at 27W. Its wedge base design means it requires no separate metal base, as the glass envelope itself acts as the retention mechanism.
• The 1998 LSS uses the 2356, a dual-filament bulb with a BAY15d bayonet base. The BAY15d base features two pins offset at different heights to ensure correct orientation during installation.
• The 1997 LSS uses the 2456, a festoon bulb intended for specialty applications. Festoon bulbs are cylindrical in shape and mount by contact pressure at each end rather than by a base socket.
• The 1996 LSS uses the 2057, a dual-filament bulb with a BAY15d bayonet base rated at 26.9W on its high filament and 8W on its low filament. It is noted as a brighter variant of the 1157.
• Because each model year of the Oldsmobile LSS specifies a distinct bulb type with a different base design, the four bulbs are not interchangeable across years without socket modification.
• The shift from dual-filament types in 1996 and 1998 to a single-filament type in 1999 reflects a change in the circuit design used for the back up light function across these model years.
• The 2356 and 2057 share the same BAY15d bayonet base, but they are specified for different model years and carry different electrical ratings, making substitution between them a matter requiring careful verification of wattage compatibility.