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HOMESERVICE MANUALSSUBARU2005OUTBACK I, STANDARDREPAIR AND DIAGNOSISENGINE PERFORMANCETESTING & DIAGNOSISENGINE CONTROLS - ENGINE (DIAGNOSTICS) (H4SO)DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)DTC P1400 FUEL TANK PRESSURE CONTROL SOLENOID VALVE CIRCUIT LOW

2005 Subaru Outback i, Standard

DTC P1400 Fuel Tank Pressure Control Solenoid Valve Circuit Low

2005 Subaru Outback i, StandardSECTION DTC P1400 Fuel Tank Pressure Control Solenoid Valve Circuit Low

DTC DETECTING CONDITION:

Two consecutive driving cycles with fault
GENERAL DESCRIPTION < Ref. to DTC P1400 FUEL TANK PRESSURE CONTROL SOLENOID VALVE CIRCUIT LOW , Diagnostic Trouble Code (DTC) Detecting Criteria. >

CAUTION: After repair or replacement of faulty parts, conduct CLEAR MEMORY MODE < Ref. to , OPERATION , Clear Memory Mode.> and INSPECTION MODE < Ref. to , PROCEDURE , Inspection Mode.>.

WIRING DIAGRAM:

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

Courtesy of SUBARU OF AMERICA, INC.

DTC P1400 FUEL TANK PRESSURE CONTROL SOLENOID VALVE CIRCUIT LOW DIAGNOSIS

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) No. 12 (+) - Chassis ground (-):	Is the voltage more than 10 V?	Go to step 2.	Go to step 3.
2. CHECK POOR CONTACT. Check 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) No. 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) No. 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 POOR CONTACT. Check 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.

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.