DTC P0458 - Evaporative Emission Control System Purge Control Valve Circuit Low -

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

DTC DETECTING CONDITION:
- Two consecutive driving cycles with malfunction
TROUBLE SYMPTOM:
- Erroneous idling

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: Evaporative Emission Control System Purge Control 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 ON. Measure voltage between ECM and chassis ground. Connector & terminal (B134) No. 29 (+) - Chassis ground (-):	Is the measured value more than 10 V?	Even if MIL lights up, the circuit has returned to a normal condition at this time. Contact with SOA service center. NOTE: Inspection by DTM is required, because probable cause is deterioration of multiple parts.	Go to step 2.
2 CHECK HARNESS BETWEEN PURGE CONTROL SOLENOID VALVE AND ECM CONNECTOR. Turn ignition switch to OFF. Disconnect connectors from purge control solenoid valve and ECM. Measure resistance of harness between purge control solenoid valve connector and engine ground. Connector & terminal (E4) No. 2 - Engine ground:	Is the measured value more than 1 Ma?	Go to step 3.	Repair 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 resistance of harness between ECM and purge control solenoid valve of harness connector. Connector & terminal (B134) No. 29 - (E4) No. 2:	Is the measured value less than 1 Ω?	Go to step 4.	Repair 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 purge control solenoid valve. Measure resistance between purge control solenoid valve terminals. Terminals No. 1 - No. 2:	Is the measured value within 10 to 100 Ω?	Go to step 5.	Replace purge control solenoid valve. < Ref. to PURGE CONTROL SOLENOID VALVE . >
5 CHECK POWER SUPPLY TO PURGE CONTROL SOLENOID VALVE. Turn ignition switch to ON. Measure voltage between purge control solenoid valve and engine ground. Connector & terminal (E4) No. 1 (+) - Engine ground (-):	Is the measured value more than 10 V?	Go to step 6.	Repair 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 poor contact in purge control solenoid valve connector.	Contact with SOA service center. NOTE: Inspection by DTM is required, because probable cause is deterioration of multiple parts.