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: Use the check board when measuring the ECM terminal voltage and resistance. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>General Description>PREPARATION TOOL>HOW TO USE CHECK BOARD .

Wiring diagram:

Engine Electrical System Ref. to WIRING SYSTEM (CROSSTREK MODEL)>Engine Electrical System>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

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 & 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.
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)>PURGE CONTROL SOLENOID VALVE .

No: Repair the poor contact of ECM connector.