Diagram reference number 1 in the image below:
" Fitment: 2009 NISSAN SENTRA SE-R - 4 door

Application Notes: Incl.Pulley

Category: Cooling

SubCategory: Water Pump and Related Components

Position: General

Part Number: B1010F461B


This is a Engine Water Pump that fits the 2009 NISSAN SENTRA SE-R - 4 door with the QR25DE engine. The Engine Water Pump is designed by NISSAN to be part of the Cooling-Water Pump and Related Components. The Engine Water Pump has a position on the vehicle of General. The 2009 NISSAN SENTRA Engine Water Pump is a factory made NISSAN OEM part and it comes with a 12 month 12,000 mile warranty (parts only). Do not be fooled by an aftermarket NISSAN SENTRA Engine Water Pump! Buy a factory NISSAN part and receive peace of mind!
This factory part has a part number of B1010F461B.