Wiring Diagram:

WARNING: This page is about a different variant/trim than selected.

Fig 1: Wiring Diagram - DTC P0451 Evaporative Emission Control System Pressure Sensor

G03829049

Courtesy of SUBARU OF AMERICA, INC.

DTC P0451 DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1. CHECK FOR ANY OTHER DTC ON DISPLAY.	Is any other DTC displayed?	Inspect the relevant DTC using "List of Diagnostic Trouble Code (DTC)". < Ref. to , LIST OF DIAGNOSTIC TROUBLE CODE (DTC) . >	Go to step 2.
2. CHECK FUEL FILLER CAP. Turn ignition switch to OFF. Open the fuel flap.	Is the fuel filler cap tightened securely?	Go to step 3.	Tighten fuel filler cap securely.
3. CHECK PRESSURE/VACUUM LINE. NOTE: Check the following items. Disconnection, leakage and clogging of the vacuum hoses and pipes between fuel tank pressure sensor and fuel tank Disconnection, leakage and clogging of air ventilation hoses and pipes between fuel filler pipe and fuel tank	Is there any fault in pressure/vacuum line?	Repair or replace the hoses and pipes.	Replace the fuel tank pressure sensor. < Ref. to FUEL TANK PRESSURE SENSOR . >