DTC P0134: A/F/O2 Sensor Circuit No Activity Detected Bank 1 Sensor 1: Notes

DTC detecting condition:

Immediately at fault recognition

CAUTION: After servicing or replacing faulty parts, perform Clear Memory Mode Ref. to OPERATION , Clear Memory Mode., and Inspection Mode Ref. to PROCEDURE , Inspection Mode..

Wiring diagram:

Engine electrical system Ref. to Engine Electrical System .

Fig 1: A/F/O2 Sensor Circuit No Activity Detected Bank 1 Sensor 1 Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

Step	Check	Yes	No
1 CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR. Turn the ignition switch to OFF. Disconnect the connector from ECM. Disconnect the connectors from front oxygen (A/F) sensor. Measure the resistance of harness between ECM connector and front oxygen (A/F) sensor connector. Connector & terminal (B136) No. 19 - (E24) No. 3: (B136) No. 18 - (E24) No. 4:	Is the resistance less than 1 Ω?	Go to step 2.	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit in harness between ECM connector and front oxygen (A/F) sensor connector Poor contact of coupling connector
2 CHECK FOR POOR CONTACT. Check for poor contact of ECM and front oxygen (A/F) sensor connector.	Is there poor contact of ECM or front oxygen (A/F) sensor connector?	Repair the poor contact of ECM or front oxygen (A/F) sensor connector.	Replace the front oxygen (A/F) sensor. Ref. to Front Oxygen (A/F) Sensor .