Pontiac Sunbird Back Up Light Bulb Size

The Pontiac Sunbird back up light utilizes 889, 1156, and P21W bulb sizes depending on the specific version of the vehicle. Data for the bulb sizes covers the range from 1976 to 1994.

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

Bulb Size by Year Range

Years	Bulb Size
1993-1994	889
1989-1992	1156
1976-1980	1156

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament halogen bulb with PGJ13 base. 12V, 37.5W.	889
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156

Other Locations

Additional Notes

The Pontiac Sunbird uses two distinct bulb types across its back up light specifications: the 1156 and the 889, and these two types are not interchangeable due to differences in base design and wattage.
The 1156 bulb is specified for the Sunbird across 1976-1980 and 1989-1992, making it the more widely applied of the two types in this application.
The 889 bulb is specified for the 1993-1994 Sunbird, representing a shift from the 1156 used in prior model years.
The 1156 is a single-filament bulb operating at 12V and 21W, fitted with a BA15s bayonet base, which uses a single locating pin for installation.
The 889 is a single-filament halogen bulb operating at 12V and 37.5W, fitted with a PGJ13 base, a pin-style base type distinct from the bayonet design of the 1156.
The 889 draws 37.5W compared to the 21W of the 1156, meaning the halogen unit produces a notably higher light output for the same 12V supply.
Both bulb types conform to ANSI standards applicable in the United States and Canada.
The base types of the two bulbs are physically incompatible with each other, as the BA15s bayonet base and the PGJ13 pin base require different socket designs in the vehicle.