DTC P0459 - Evaporative Emission Control System Purge Control Valve Circuit High -

WARNING: This page is about a different variant/trim than selected.

DTC DETECTING CONDITION:
- Two consecutive driving cycles with malfunction
TROUBLE SYMPTOM:
- Erroneous idling

CAUTION: After repair or replacement of malfunctioning parts, conduct Clear Memory Mode < Ref. to OPERATION , CLEAR MEMORY MODE > and INSPECTION MODE < Ref. to OPERATION , INSPECTION MODE. >

WIRING DIAGRAM:

Fig 1: Evaporative Emission Control System Purge Control Valve Wiring Diagram
Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1 CHECK OUTPUT SIGNAL FROM ECM. Turn ignition switch to OFF. Connect test mode connector at the lower portion of instrument panel (on the driver's side), to the side of the center console box. Turn ignition switch to ON. While operating purge control solenoid valve, measure voltage between ECM and chassis ground. NOTE: Purge control solenoid valve operation can be executed using Subaru Select Monitor. For procedure, < Ref. to COMPULSORY VALVE OPERATION CHECK MODE . > Connector & terminal (B134) No. 29 (+) - Chassis ground (-):	Is the measured value more than 10 V?	Go to step 2.	Even if MIL light up, the circuit has returned to a normal condition at this time. In this case, repair poor contact in ECM connector.
2 CHECK OUTPUT SIGNAL FROM ECM. Turn ignition switch to ON. Measure voltage between ECM and chassis ground. Connector & terminal (B134) No. 29 (+) - Chassis ground (-):	Is the measured value more than 10 V?	Go to step 4.	Go to step 3.
3 CHECK POOR CONTACT. Check poor contact in ECM connector.	Is there poor contact in ECM connector?	Repair poor contact in ECM connector.	Replace ECM. < Ref. to ENGINE CONTROL MODULE . >
4 CHECK HARNESS BETWEEN PURGE CONTROL SOLENOID VALVE AND ECM CONNECTOR. Turn ignition switch to OFF. Disconnect connector from purge control solenoid valve. Turn ignition switch to ON. Measure voltage between ECM and chassis ground. Connector & terminal (B134) No. 29 (+) - Chassis ground (-).	Is the measured value more than 10 V?	Repair battery short circuit in harness between ECM and purge control solenoid valve connector. After repair, replace ECM. < Ref. to ENGINE CONTROL MODULE . >	Go to step 5.
5 CHECK PURGE CONTROL SOLENOID VALVE. Turn ignition switch to OFF. Measure resistance between purge control solenoid valve terminals. Terminals No. 1 - No. 2:	Is the measured value less than 1 Ω?	Replace purge control solenoid valve < Ref. to PURGE CONTROL SOLENOID VALVE > and ECM < Ref. to ENGINE CONTROL MODULE . >	Go to step 6.
6 CHECK POOR CONTACT. Check poor contact in ECM connector.	Is there poor contact in ECM connector?	Repair poor contact in ECM connector.	Replace ECM. < Ref. to ENGINE CONTROL MODULE . >