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

2022 Subaru Impreza Base, 4D Sedan, Automatic CVT TransSECTION Notes
  1. 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 (IMPREZA MODEL)>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM . Ref. to WIRING SYSTEM (CROSSTREK MODEL (EXCEPT FOR HEV))>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM .

    • IMPREZA MODEL
      G13614639Courtesy of SUBARU OF AMERICA, INC.
    • CROSSTREK MODEL
      G13614640Courtesy of SUBARU OF AMERICA, INC.
    CAUTION:

    Use the check board when measuring the ECM terminal voltage and resistance. Ref. to  ENGINE (DIAGNOSTICS) (H4DO 2.0 (EXCEPT FOR HEV))>GENERAL DESCRIPTION>PREPARATION TOOL>HOW TO USE CHECK BOARD  . 

  1. CHECK HARNESS BETWEEN ECM AND PURGE CONTROL SOLENOID VALVE (SHORT TO POWER SUPPLY)  .
    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 chassis ground.

      Connector and terminal 

      (E158) No. 9 (+) - Chassis 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.

  2. CHECK PURGE CONTROL SOLENOID VALVE  .
    1. Turn the ignition switch to OFF.
    2. Measure the resistance between purge control solenoid valve terminals.

      Terminals 

      No. 1 - No. 2:

    Is the resistance less than 1 Ω?

    Yes:  Replace the purge control solenoid valve. Ref. to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (H4DO (EXCEPT FOR HEV))>PURGE CONTROL SOLENOID VALVE .

    No:  Repair the poor contact of ECM connector.

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.