Subaru IMPREZA GD 2007 Series Manual page 240

asieps_tobira_IM_US.book 131 ページ ２０１２年１月１７日 火曜日 午後３時４８分
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 CHECK FRONT OXYGEN (A/F) SENSOR
CONNECTOR AND COUPLING CONNEC-
TOR.
2 CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from the ECM
and front oxygen (A/F) sensor.
3) Measure the resistance between ECM and
chassis ground.
Connector & terminal
(B135) No. 9 — Chassis ground:
(B135) No. 8 — Chassis ground:
3 CHECK POOR CONTACT.
Check poor contact of front oxygen (A/F) sensor
connector.
Check
Has water entered the connec-
tor?
Is the resistance 1 MΩ or
more?
Is there poor contact in front
oxygen (A/F) sensor connector?
EN(H4SO)(diag)-131
ENGINE (DIAGNOSTICS)
Yes No
Completely Go to step 2.
remove any water
inside.
Go to step 3. Repair short cir-
cuit of the harness
to ground between
ECM and front oxy-
gen (A/F) sensor
connector.
Repair the poor Replace the front
contact of the front oxygen (A/F) sen-
oxygen (A/F) sen- sor. <Ref. to
sor connector. FU(H4SO)-36,
Front Oxygen (A/F)
Sensor.>