Cadillac Catera Back Up Light Bulb Size

The Cadillac Catera back up light utilizes 1156 and P21W bulb sizes according to the provided specifications for the lighting components. Data for the specific bulbs covers the range from 1997 through 2001.

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
1997-2001	1156

Bulb Specifications

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

Other Locations

Additional Notes

The Cadillac Catera uses the 1156 bulb for the back up light position across all listed model years, spanning 1997-2001.
The 1156 is an ANSI-standardized bulb type recognized across the United States and Canada, meaning it conforms to a defined set of electrical and physical specifications shared by all compliant manufacturers.
The 1156 operates on a 12-volt electrical system and draws 21 watts, which is consistent with standard automotive reverse lighting applications.
The 1156 uses a BA15s bayonet base, a single-contact mount where the "s" designation indicates a single pin, distinguishing it from double-contact bayonet variants.
The single-filament construction of the 1156 means it serves one lighting function only, which aligns with its dedicated use in the back up light position on the Cadillac Catera.
Because the BA15s base is a single-contact design, it is not interchangeable with the BA15d base, which carries two offset pins and is used in dual-filament applications.