Subaru 2009 IMPREZA Service Manual page 1495

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
1 CHECK BLOW-BY HOSE.
Check the blow-by hose condition.
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
(B134) No. 30 — (E80) No. 2:
3 CHECK HARNESS BETWEEN ECM AND
PCV HOSE ASSEMBLY CONNECTOR.
Measure the resistance between PCV hose
assembly connector and chassis ground.
Connector & terminal
(B134) No. 30 — Chassis ground:
4 CHECK GROUND CIRCUIT OF PCV HOSE
ASSEMBLY.
Measure the resistance of harness between
PCV hose assembly connector and engine
ground.
Connector & terminal
(E80) No. 1 — Engine ground:
5 CHECK PCV HOSE ASSEMBLY.
Measure the resistance between the PCV hose
assembly terminals.
Terminals
No. 1 — No. 2:
Check
Is there any disconnection or
crack in blow-by hose?
Is the resistance less than 1 ? Go to step 3.
Is the resistance 1 M or
more?
Is the resistance less than 5 ? Go to step 5.
Is the resistance less than 1 ? Repair the poor
EN(H4DOTC)(diag)-274
Yes No
Repair or replace Go to step 2.
the blow-by hose.
Repair the harness
and connector.
NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
ECM and
hose
connector
• Poor contact of
coupling connector
Go to step 4. Repair the short
circuit to ground in
harness between
ECM and PCV
hose assembly
connector.
Repair the open
circuit in harness
between PCV hose
assembly connec-
tor and engine
ground.
Replace the PCV
contact of ECM hose assembly.
and PCV hose <Ref. to
assembly connec- EC(H4DOTC)-23,
tor. PCV Hose Assem-
bly.>
PCV
assembly