The Lexus RC350 back up light requires a bulb size of 921 for proper installation and function within the rear lighting assembly. Available data covers the range from 2015 through 2018 for the specified vehicle components.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 921 bulb is the sole bulb type specified across all back up light positions on the Lexus RC350, covering both the standard and inner back up light applications.
The 921 is an ANSI-standardized bulb, meaning its physical and electrical specifications are governed by a recognized North American standard applicable in the US and Canada.
The 921 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 and is retained by socket tension alone.
The bulb operates at 12 volts and draws 16 watts, consistent with standard automotive incandescent reverse light applications.
The standard back up light on the Lexus RC350 uses the 921 bulb across the 2015-2018 model years.
The inner back up light position uses the same 921 bulb across the 2015-2019 model years.
The 2015 inner back up light fitment carries a production date qualifier of "From 09/2014," indicating the specification applies only to vehicles produced from September 2014 onward within that model year.
Because both the standard and inner back up light positions share the same 921 bulb, a single bulb type services all reverse lighting sockets on the RC350 models covered by these specifications.
The T15 wedge base of the 921 is not interchangeable with other common wedge base sizes such as T10 or T20, and substitution with those types would result in an improper fit.