Mercedes-Benz GLC300 Back Up Light Bulb Size

The Mercedes-Benz GLC300 back up light requires a bulb size of 921 for proper installation and function within the rear lighting assembly. Data for the specific component covers a range from 2016 through 2022.

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
2020-2022	921
2019	921 (With Halogen Capsule Headlamps)
2016-2018	921

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Wedge bulb (T15). 12V, 16W.	921

Other Locations

Additional Notes

The 921 bulb is the specified back up light size across all listed model years of the Mercedes-Benz GLC300, spanning 2016-2022.
The 921 is classified as a T15 wedge-base bulb, meaning it uses a plastic wedge-shaped base rather than a metal pin or bayonet fitting, and is inserted directly into a socket without a separate holder.
The bulb operates at 12 volts and draws 16 watts, which is consistent with standard automotive electrical systems.
The 921 designation follows ANSI standards recognized in both the United States and Canada, indicating a standardized specification for bulb geometry and electrical performance.
The 2019 Mercedes-Benz GLC300 carries a notation specifying compatibility with vehicles equipped with Halogen Capsule Headlamps, distinguishing that trim or configuration from others in the same model year.