Wiring Diagram:

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

Fig 1: Wiring Diagram - DTC P1400 Fuel Tank Pressure Control Solenoid Valve Circuit Low

G03829070

Courtesy of SUBARU OF AMERICA, INC.

DTC P1400 DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1. CHECK OUTPUT SIGNAL FROM ECM. Turn ignition switch to ON. Measure the voltage between ECM and chassis ground. Connector & terminal (B134) 12 (+) - Chassis ground (-):	Is the voltage more than 10 V?	Go to step 2.	Go to step 3.
2. CHECK FOR POOR CONTACT. Check for poor contact in ECM connector.	Is there poor contact in ECM connector?	Repair poor contact in ECM connector.	Contact SOA Service Center.
3. CHECK HARNESS BETWEEN FUEL TANK PRESSURE CONTROL SOLENOID VALVE AND ECM CONNECTOR. Turn ignition switch to OFF. Disconnect the connectors from fuel tank pressure control solenoid valve and ECM. Measure the resistance of harness between fuel tank pressure control solenoid valve connector and chassis ground. Connector & terminal (R68) 2 - Chassis ground:	Is the resistance less than 10 Ω?	Repair short circuit to ground in harness between ECM and fuel tank pressure control solenoid valve connector.	Go to step 4.
4. CHECK HARNESS BETWEEN FUEL TANK PRESSURE CONTROL SOLENOID VALVE AND ECM CONNECTOR. Measure the resistance of harness between ECM and fuel tank pressure control solenoid valve connector. Connector & terminal (B134) No. 12 - (R68) No. 2:	Is the resistance less than 1 Ω?	Go to step 5.	Repair harness and connector. NOTE: In this case, repair the following: Open circuit in harness between ECM and fuel tank pressure control solenoid valve connector Poor contact in coupling connector
5. CHECK FUEL TANK PRESSURE CONTROL SOLENOID VALVE. Measure the resistance between fuel tank pressure control solenoid valve terminals. Terminals No. 1 - No. 2:	Is the resistance 10 - 100 Ω?	Go to step 6.	Replace the fuel tank pressure control solenoid valve. < Ref. to PURGE CONTROL SOLENOID VALVE . >
6. CHECK POWER SUPPLY TO FUEL TANK PRESSURE CONTROL SOLENOID VALVE. Turn ignition switch to ON. Measure the voltage between fuel tank pressure control solenoid valve and chassis ground. Connector & terminal (R68) 1 (+) - Chassis ground (-):	Is the voltage more than 10 V?	Go to step 7.	Repair harness and connector. NOTE: In this case, repair the following: Open circuit in harness between main relay and fuel tank pressure control solenoid valve connector Poor contact in coupling connector Poor contact in main relay connector
7. CHECK FOR POOR CONTACT. Check for poor contact in fuel tank pressure control solenoid valve connector.	Is there poor contact in fuel tank pressure control solenoid valve connector?	Repair poor contact in fuel tank pressure control solenoid valve connector.	Contact SOA Service Center.