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

DTC detecting condition:

Detected when two consecutive driving cycles with fault occur.

Trouble symptom:

Improper idling

CAUTION:

After servicing or replacing faulty parts, perform Clear Memory Mode Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>CLEAR MEMORY MODE>OPERATION , and inspection mode Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>INSPECTION MODE>PROCEDURE ..
Use the check board when measuring the ECM terminal voltage and resistance.

Wiring diagram:

Engine Electrical System Refer to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM .

G11577188

Courtesy of SUBARU OF AMERICA, INC.

CHECK HARNESS BETWEEN ECM AND PURGE CONTROL SOLENOID VALVE 1 CONNECTOR.
1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Disconnect the connector from purge control solenoid valve 1.
4. Turn the ignition switch to ON.
5. Measure the voltage between ECM connector and engine ground.
  Connector & terminal
  
  (E159) No. 4 (+) - Engine ground (-):
Is the voltage 10 V or more?

Yes: Repair the short circuit to power in harness between ECM connector and purge control solenoid valve 1 connector.

No: Go to 2.
CHECK PURGE CONTROL SOLENOID VALVE 1.
1. Turn the ignition switch to OFF.
2. Measure the resistance between purge control solenoid valve 1 terminals.
  Terminals
  
  No. 1 - No. 2:
Is the resistance less than 1 Ω?

Yes: Replace the purge control solenoid valve 1. Refer to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (EXCEPT FOR STI)>PURGE CONTROL SOLENOID VALVE .

No: Repair the poor contact of ECM connector.