Chevrolet Impala Limited Map Light Bulb Size

The Chevrolet Impala Limited map light requires a 578 bulb size for proper illumination. The replacement chart covers 2014 to 2016 vehicle production years with corresponding bulb specifications.

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
2014-2016	578

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Festoon bulb, 41mm length, end-cap contacts. 12V, 12W.	578

Other Locations

Additional Notes

The 578 bulb is the map light specification for the Chevrolet Impala Limited across the 2014-2016 model years.
The 578 is a festoon-type bulb, meaning it is cylindrical in shape and mounts by pressing its end caps into spring-loaded contacts rather than using a socket base.
The 578 bulb has a length of 41mm, which is the contact-to-contact span that must match the fixture's spring clip spacing for proper installation.
The 578 operates at 12 volts and 12 watts, consistent with standard automotive low-voltage electrical systems.
The 578 designation follows ANSI standards recognized in both the United States and Canada, indicating a standardized specification shared across multiple manufacturers and product lines.
Because festoon bulbs are sized by their physical length, substituting a festoon bulb of a different length, such as a 36mm or 44mm unit, would result in a fitment mismatch regardless of voltage or wattage compatibility.