Subaru IMPREZA GD 2007 Series Manual page 1460

asieps_tobira_IM_US.book 129 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 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 of harness between
ECM and front oxygen (A/F) sensor connector.
Connector & terminal
(B135) No. 9 — (B18) No. 4:
(B135) No. 8 — (B18) No. 3:
2 CHECK POOR CONTACT.
Check poor contact of front oxygen (A/F) sensor
connector.
Check
Is the resistance less than 1 Ω? Go to step 2.
Is there poor contact in front
oxygen (A/F) sensor connector?
EN(STI)(diag)-129
ENGINE (DIAGNOSTICS)
Yes No
Repair the harness
and connector.
NOTE:
In this case, repair
the following item:
• Open circuit of
harness between
ECM and front oxy-
gen (A/F) sensor
connector
• Poor contact in
front oxygen (A/F)
sensor connector
• Poor contact in
ECM 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(H4DOTC)-46,
Front Oxygen (A/F)
Sensor.>