DTC P0459: EVAP System (CPC) Purge Control Valve "A" Circuit High: Notes

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DTC detecting condition:

Detected when two consecutive driving cycles with fault occur.

Trouble symptom:

Improper idling

Wiring diagram:

Engine Electrical System Ref. to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM .

Courtesy of SUBARU OF AMERICA, INC.

CAUTION: Use the check board when measuring the ECM terminal voltage and resistance. Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>General Description>PREPARATION TOOL>HOW TO USE CHECK BOARD .

NOTE: After the faulty parts are repaired or replaced, perform the final check in Basic Diagnostic Procedure. Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Basic Diagnostic Procedure>PROCEDURE .

CHECK HARNESS BETWEEN ECM AND PURGE CONTROL SOLENOID VALVE CONNECTOR .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Disconnect the connector from the purge control solenoid valve.
4. Turn the ignition switch to ON.
5. Measure the voltage between ECM connector and engine ground.
  Connector & terminal
  
  (E158) No. 2 (+) - Engine ground (-):
Is the voltage 10 V or more?

Yes : Repair the short circuit to power in the harness between ECM connector and purge control solenoid valve connector.

No : Go to 2.
CHECK PURGE CONTROL SOLENOID VALVE .
1. Turn the ignition switch to OFF.
2. Check the purge control solenoid valve. Ref. to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (H4DOTC)>Purge Control Solenoid Valve>INSPECTION .
Is the check result OK?

Yes : Repair the poor contact of ECM connector.

No : Replace the purge control solenoid valve. Ref. to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (H4DOTC)>PURGE CONTROL SOLENOID VALVE .