WARNING: This page is about a different car, the 2013 Honda Fit, 2012 Honda Fit, 2011 Honda Fit, 2010 Honda Fit, and 2009 Honda Fit. However, it is still accessible from the selected car via links, so may be relevant.
The FTP sensor converts fuel tank absolute pressure into an electrical input to the ECM/PCM.
Fig 1: Identifying Sectional View Of Fuel Tank Pressure Sensor