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Diagnostic Procedure

WARNING: This page is about a different car, the 2013 Subaru Forester. However, it is still accessible from the selected car via links, so may be relevant.
DIAGNOSTIC PROCEDURE

Step Check Yes No
1 CHECK BLOW-BY HOSE. 
Check the blow-by hose condition.
Is there any disconnection or crack in blow-by hose? Repair or replace the blow-by hose. Go to step 2. 
2 CHECK HARNESS BETWEEN ECM AND PCV HOSE ASSEMBLY CONNECTOR. 
  1. Turn the ignition switch to OFF.
  2. Disconnect the connectors from the ECM and PCV hose assembly.
  3. Measure the resistance of harness between ECM and PCV hose assembly connector.

    Connector & terminal 

    (B137) No. 12 - (E80) No. 2: 

Is the resistance less than 1 Ω? Go to step 3.  Repair the harness and connector.
NOTE: In this case, repair the following item:
  • Open circuit in harness between ECM and PCV hose assembly connector
  • Poor contact of coupling connector
3 CHECK HARNESS BETWEEN ECM AND PCV HOSE ASSEMBLY CONNECTOR. 
Measure the resistance between PCV hose assembly connector and chassis ground.
Connector & terminal 
(B137) No. 12 - Chassis ground: 
Is the resistance 1 MΩ or more? Go to step 4.  Repair the short circuit to ground in harness between ECM and PCV hose assembly connector.
4 CHECK HARNESS BETWEEN LEAK DIAGNOSIS CONNECTORS. 
Measure the resistance of harness between leak diagnosis connectors.
Connector & terminal 
(E80) No. 1 - (E87) No. 1: 
(E87) No. 2 - (E88) No. 1: 
Is the resistance less than 1 Ω? Go to step 5.  Repair the open circuit in the wiring harness between leak diagnosis connectors.
5 CHECK GROUND CIRCUIT OF PCV HOSE ASSEMBLY. 
Measure the resistance of harness between PCV hose assembly connector and engine ground.
Connector & terminal 
(E80) No. 2 - Engine ground: 
Is the resistance less than 5 Ω? Go to step 6.  Repair the open circuit in harness between PCV hose assembly connector and engine ground.
6 CHECK PCV HOSE ASSEMBLY. 
Measure the resistance between terminals of each leak diagnosis connector.
Terminals 
No. 1 - No. 2: 
Is the resistance less than 1 Ω at all measurement? Repair the poor contact of ECM and PCV hose assembly connector. Replace the PCV hose assembly. < Refer to PCV HOSE ASSEMBLY