Mercedes-Benz C350e Back Up Light Bulb Size

The Mercedes-Benz C350e back up light requires a 921 bulb size for proper installation and function within the rear lighting assembly. Available data for the specified bulb covers the range from 2016 to 2018.

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
2016-2018	921 (With Halogen Capsule Headlamps)

Bulb Specifications

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

Other Locations

Additional Notes

The Mercedes-Benz C350e uses the 921 bulb for the backup light across the 2016-2018 model years, with the condition that the vehicle is equipped with Halogen Capsule Headlamps.
The 921 is an ANSI-standardized bulb type recognized across the United States and Canada, establishing a consistent specification baseline for the North American market.
The 921 bulb uses a wedge-style base, designated T15, which refers to a tubular bulb body approximately 15 eighths of an inch wide. This base type requires no locking pins or twist mechanisms, as the socket holds the bulb through friction alone.
The 921 operates at 12 volts and 16 watts, which is consistent with standard automotive electrical systems and places it in the lower wattage range for incandescent backup lighting.
The Halogen Capsule Headlamp qualifier on all three model years indicates that the backup light bulb specification is tied to a specific trim or factory lighting configuration, meaning vehicles with a different headlamp type may not share this fitment.