The Lexus RX330 back up light requires a 921 bulb size for proper installation and function within the specified lighting assembly. Data for the bulb size covers the range from 2004 to 2006.
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 size specified across all back up light positions on the Lexus RX330 for the 2004-2006 model years.
The 921 is an ANSI-standardized bulb used in the United States and Canada, operating at 12 volts with a 16-watt output.
The 921 uses a wedge-style base, classified under the T15 designation, which refers to a tubular bulb body approximately 15/8 of an inch wide.
A wedge base bulb has no metal pins or bayonet tabs; the glass envelope itself is pinched at the base and held in place by tension within the socket.
The inner back up light on the 2006 RX330 carries a production date qualifier, specifying the 921 bulb only for vehicles built up to February 2006.
The standard back up light and the inner back up light share the same 921 bulb size across the 2004-2005 model years without any date-based restrictions.
Because both light positions use the same bulb size, a single 921 bulb type covers all back up light sockets on the 2004-2005 RX330.
The T15 wedge form factor is a common fitment in reverse and interior lighting applications, and the 921 is a widely available size within that category.