DTC P0458 Evaporative Emission System Purge Control Valve Circuit Low

WARNING: This page is about a different car, the 2006 Subaru Outback. However, it is still accessible from the selected car via links, so may be relevant.

DTC DETECTING CONDITION:

Two consecutive driving cycles with fault
GENERAL DESCRIPTION < Ref. to DTC P0458 EVAPORATIVE EMISSION SYSTEM PURGE CONTROL VALVE CIRCUIT LOW , Diagnostic Trouble Code (DTC) Detecting Criteria. >

TROUBLE SYMPTOM:

Erroneous idling

CAUTION: After repair or replacement of faulty parts, perform Clear Memory Mode < Ref. to OPERATION , Clear Memory Mode. > and Inspection Mode < Ref. to PROCEDURE , Inspection Mode. >.

WIRING DIAGRAM:

Fig 1: Evaporative Emission System Purge Control Valve - Wiring Diagram

DTC P0458 EVAPORATIVE EMISSION SYSTEM PURGE CONTROL VALVE CIRCUIT LOW - DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1 CHECK OUTPUT SIGNAL OF ECM. Turn the ignition switch to ON. Measure the voltage between ECM and chassis ground. Connector & terminal (B137) No. 29 (+) - 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 MΩ?	Go to step 3.	Repair the ground short circuit of 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. Connector & terminal (B137) No. 29 - (E4) No. 2:	Is the resistance less than 1 Ω?	Go to step 4.	Repair the open circuit of harness between ECM and purge control solenoid valve connector. NOTE: In this case, repair the following item: 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 between 10 and 100 Ω?	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 of harness between main relay and purge control solenoid valve connector.
6 CHECK POOR CONTACT. Check poor contact of purge control solenoid valve connector.	Is there poor contact of purge control solenoid valve connector?	Repair the poor contact of purge control solenoid valve connector.	Replace the ECM. < Ref. to ENGINE CONTROL MODULE (ECM) . >