Oldsmobile Cutlass Ciera Back Up Light Bulb Size

The Oldsmobile Cutlass Ciera back up light utilizes 1156 and P21W bulb sizes according to the provided technical specifications for the lighting system. Data for the lighting components covers the range from 1982 through 1990.

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
1982-1990	1156

Bulb Specifications

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

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Additional Notes

The Oldsmobile Cutlass Ciera uses the 1156 bulb for its back up light across all model years listed in the specifications, spanning 1982-1990.
The 1156 is a single-filament bulb, meaning it serves one lighting function rather than combining two, such as stop and tail duties.
It operates on 12 volts at 21 watts, which is consistent with standard automotive electrical systems of that era.
The 1156 uses a BA15s bayonet base, a single-contact mount where the bulb is inserted and twisted to lock into place.
The BA15s designation indicates a 15mm base width with a single contact point at the base, distinguishing it from the dual-contact BA15d used in two-filament applications.
The 1156 is an ANSI-standardized bulb recognized in both the United States and Canada, indicating a defined and consistent specification for wattage, voltage, and base type across manufacturers.
Because the same bulb size applies uniformly across the entire 1982-1990 production span of the Cutlass Ciera, a single replacement part number covers all listed model years for this function.
The BA15s base is not interchangeable with the BA15d base; substituting a dual-contact bulb in a single-contact socket results in improper fitment.