DTC P1420 - Fuel Tank Pressure Control Solenoid Valve Circuit High -

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

DTC DETECTING CONDITION:
- Two consecutive driving cycles with malfunction
CAUTION: After repair or replacement of malfunctioning parts, conduct Clear Memory Mode < Ref. to OPERATION , CLEAR MEMORY MODE > and INSPECTION MODE < Ref. to OPERATION , INSPECTION MODE. >
WIRING DIAGRAM:

Fig 1: Fuel Tank Pressure Control Solenoid Valve Wiring Diagram
Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1 CHECK OUTPUT SIGNAL FROM ECM. Turn ignition switch to OFF. Connect test mode connector at the lower portion of instrument panel (on the driver's side), to the side of the center console box. Turn ignition switch to ON. Measure voltage between ECM and chassis ground. NOTE: Pressure control solenoid valve operation car be executed using Subaru Select Monitor. For procedure, < Ref. to COMPULSORY VALVE OPERATION CHECK MODE . > Connector & terminal (B134) No. 4 (+) - Chassis ground (-):	Is the measured value within 0 to 10 V?	Go to step 2.	Even if MIL light up, the circuit has returned to a normal condition at this time. In this case, repair poor contact in ECM connector.
2 CHECK OUTPUT SIGNAL FROM ECM. Turn ignition switch to ON. Measure voltage between ECM and chassis ground. Connector & terminal (B134) No. 4 (+) - Chassis ground (-):	Is the measured value more than 10 V?	Go to step 4.	Go to step 3.
3 CHECK POOR CONTACT. Check poor contact in ECM connector.	Is there poor contact in ECM connector?	Repair poor contact in ECM connector.	Replace ECM. < Ref. to ENGINE CONTROL MODULE . >
4 CHECK HARNESS BETWEEN PRESSURE CONTROL SOLENOID VALVE AND ECM CONNECTOR. Turn ignition switch to OFF. Disconnect connector from pressure control solenoid valve. Turn ignition switch to ON. Measure voltage between ECM and chassis ground. Connector & terminal (B134) No. 4 (+) - Chassis ground (-):	Is the measured value more than 10 V?	Repair battery short circuit in harness between ECM and pressure control solenoid valve connector. After repair, replace ECM. < Ref. to ENGINE CONTROL MODULE . >	Go to step 5.
5 CHECK PRESSURE CONTROL SOLENOID VALVE. Turn ignition switch to OFF. Measure resistance between pressure control solenoid valve terminals. Terminals No. 1 - No. 2:	Is the measured value less than 1 Ω?	Replace pressure control solenoid valve < Ref. to PRESSURE CONTROL SOLENOID VALVE > and ECM < Ref. to ENGINE CONTROL MODULE . >	Go to step 6.
6 CHECK POOR CONTACT. Check poor contact in ECM connector.	Is there poor contact in ECM connector?	Repair poor contact in ECM connector.	Replace ECM. < Ref. to ENGINE CONTROL MODULE . >