Wiring Diagram:

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

Fig 1: Wiring Diagram - DTC P0458 Evaporative Emission Control System Purge Control Valve Circuit Low

G03830024

Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTIC PROCEDURE (DTC P0458)

Step		Check	Yes	No
1 CHECK OUTPUT SIGNAL FROM ECM. Turn the ignition switch to ON. Measure the voltage between ECM and chassis ground. Connector & terminal (B134) No. 14 (+) - Chassis ground (-):		Is the voltage more than 10 V?	Even if the malfunction indicator light illuminates, the circuit has returned to a normal condition at this time.	Go to step 2.
2 CHECK HARNESS BETWEEN PURGE CONTROL SOLENOID VALVE AND ECM CONNECTOR. Turn the ignition switch to OFF. Disconnect the connectors from purge control solenoid valve and ECM. Measure the resistance of harness between purge control solenoid valve connector and engine ground. Connector & terminal (E4) No. 2 - Engine ground:		Is the resistance more than 1 M?	Go to step 3.	Repair the ground short circuit in harness between ECM and purge control solenoid valve connector.
3 CHECK HARNESS BETWEEN PURGE CONTROL SOLENOID VALVE AND ECM CONNECTOR. Measure the resistance of harness between ECM and purge control solenoid valve of harness connector. Connector & terminal (B134) No. 14 - (E4) No. 2:		Is the resistance less than 1 ?	Go to step 4.	Repair the open circuit in harness between ECM and purge control solenoid valve connector. NOTE: In this case, repair the following: Open circuit in harness between ECM and purge control solenoid valve connector Poor contact in coupling connector
4 CHECK PURGE CONTROL SOLENOID VALVE. Remove the purge control solenoid valve. Measure the resistance between purge control solenoid valve terminals. Terminals No. 1 - No. 2:		Is the resistance 29 - 35 ?	Go to step 5.	Replace the purge control solenoid valve. < Ref. to PURGE CONTROL SOLENOID VALVE . >
5 CHECK POWER SUPPLY TO PURGE CONTROL SOLENOID VALVE. Turn the ignition switch to ON. Measure the voltage between purge control solenoid valve and engine ground. Connector & terminal (E4) No. 1 (+) - Engine ground (-):		Is the voltage more than 10 V?	Go to step 6.	Repair the open circuit in harness between main relay and purge control solenoid valve connector.
6 CHECK POOR CONTACT. Check poor contact in purge control solenoid valve connector.		Is there poor contact in purge control solenoid valve connector?	Repair the poor contact in purge control solenoid valve connector.	Replace the ECM. < Ref. to ENGINE CONTROL MODULE (ECM) . >