Acura CL Back Up Light Bulb Size

The Acura CL back up light utilizes bulb sizes 7440 and 3497 for the rear illumination system. Data for the specific components covers the time range from 1997 through 2003.

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
2001-2003	7440
1997-1999	3497

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament wedge bulb (T20). 12V, 21W.	7440
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Variant of 1156. 12V, 21W.	3497

Other Locations

Additional Notes

The Acura CL backup light specifications cover two distinct bulb types across its production years: the 7440 and the 3497, both rated at 12V and 21W.
The 7440 is a T20 wedge-base bulb, meaning it uses a plastic wedge to secure itself into the socket rather than a metal base with pins or a bayonet fitting.
The 3497 uses a BA15s bayonet base, a single-pin twist-lock mount that is a variant of the widely used 1156 bulb family.
Both bulb types are single-filament designs, which is standard for backup lights since the function requires only one consistent output state with no dimming or dual-intensity operation.
Both the 7440 and 3497 carry ANSI standardization for the US and Canadian markets, indicating they conform to defined electrical and physical specifications within those regions.
The Acura CL uses the 7440 for model years 2001-2003 and the 3497 for model years 1997-1999, reflecting a base change between the two generations of the vehicle.
Because the 7440 and 3497 use physically incompatible mounting systems, a wedge socket and a bayonet socket respectively, the two bulbs are not interchangeable despite sharing the same voltage and wattage ratings.
The 3497 is classified as a variant of the 1156, though substituting a standard 1156 in place of a 3497 would require confirming that the physical and electrical tolerances of the specific socket are compatible, as variant designations can reflect minor differences in base construction.