Pontiac Grand Am Back Up Light Bulb Size

The Pontiac Grand Am back up light utilizes 912, 3057, P21W, 1156, 2057, and 1157 bulb sizes depending on the specific production version of the vehicle. Available data for the lighting components spans from 1973 through 2000.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Back Up Light

Years	Bulb Size
1999-2000	912
1996-1998	3057
1990-1995	1156
1985-1989	2057
1980	1157
1978-1979	1156
1974-1975	1156
1973	1157

Inner Back Up Light

Years	Bulb Size
2005	2456
2004	3156
2002-2003	2456
2001	3156
2000	2456
1999	2356

Outer Back Up Light

Years	Bulb Size
1999-2005	912

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Wedge bulb (T15). Variant of 921. 12V, 12W.	912
ANSI standard (US & Canada). Dual-filament wedge bulb (T25). 12V, 27W/7W.	3057
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. Brighter variant of 1157. 12V, 26.9W/8W.	2057
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. 12V, 21W/5W.	1157
ANSI standard (US & Canada). Festoon bulb, specialty application. 12V.	2456
ANSI standard (US & Canada). Single-filament wedge bulb (T25). 12V, 27W.	3156
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. 12V.	2356

Other Locations

Additional Notes

The 912 bulb is the most frequently specified size across the Pontiac Grand Am's back up light positions, appearing in the standard back up light for 1999-2000 and in the outer back up light for 1999-2005. It is a T15 wedge bulb rated at 12V and 12W, and it is a variant of the 921.
The 1156 bulb is a single-filament type with a BA15s bayonet base, rated at 12V and 21W. It is specified for the standard back up light across the widest span of model years in these specifications, covering 1974-1975, 1978-1979, and 1990-1995.
The 2057 bulb carries a dual-filament design with a BAY15d bayonet base, rated at 12V with filaments at 26.9W and 8W. The Grand Am uses it for the standard back up light across 1985-1989, though a back up light application typically activates only one filament.
The 3057 is a dual-filament wedge bulb in the T25 form factor, rated at 12V with filaments at 27W and 7W. It is specified for the Pontiac Grand Am standard back up light for 1996-1998.
The 1157 bulb shares the BAY15d bayonet base with the 2057 but operates at lower wattage, with filaments rated at 21W and 5W. It appears in the standard back up light position for the 1973 and 1980 model years.
The inner back up light position on the Pontiac Grand Am (1999-2005) alternates between three distinct bulb types across model years. The 2356 is specified for 1999, the 2456 for 2000 and 2002-2003 and 2005, and the 3156 for 2001 and 2004, indicating that direct interchangeability between these years is not assumed.
The 3156 is a single-filament T25 wedge bulb rated at 12V and 27W. Despite sharing the T25 form factor with the dual-filament 3057, the 3156 carries only one filament, and the two are not interchangeable.
The 2456 is a festoon-style bulb rated at 12V, designated for specialty applications. Its festoon construction differs physically from the wedge and bayonet types used elsewhere in the Grand Am's back up light system.
The 2057 and 1157 bulbs both use the BAY15d bayonet base, but their wattage ratings differ. The 2057 is described as a brighter variant of the 1157, and substituting one for the other would result in a difference in output.
For model years 1999-2005, the Pontiac Grand Am back up light system is divided into separate inner and outer positions. The outer position consistently uses the 912 wedge bulb across all seven of those years, while the inner position varies by year.