EVAP Control System Overview

EVAP Control System Overview:

The EVAP system uses a fuel tank pressure sensor that is located on the top of the fuel tank sending unit in order to detect when the EVAP system is purging. When the EVAP system is not purging, the fuel tank pressure sensor will detect no change in the fuel tank vacuum. When the EVAP system is purging, the fuel tank pressure sensor will detect a vacuum in the fuel tank. A change in fuel tank pressure will be displayed on the scan tool.

If any of the following EVAP malfunctions are present
^ A leak
^ A plug
^ A malfunctioning fuel tank pressure sensor

one of the following DTCs will set:
^ P0440
^ P0442
^ P0446
^ P0452
^ P0453
^ P1441

If any of these DTCs are set, go to the DTC table for diagnosis.