DTC P0134: O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1): Wiring Diagram

Engine electrical system turbo engine model (without push button start) < Ref. to TURBO MODEL (WITHOUT PUSH BUTTON START) , WIRING DIAGRAM, Engine Electrical System. >
Engine electrical system turbo engine model (with push button start) < Ref. to TURBO MODEL (WITH PUSH BUTTON START) , WIRING DIAGRAM, Engine Electrical System. >

Fig 1: Front Oxygen Sensor Wiring Diagram
Courtesy of SUBARU OF AMERICA, INC.

DTC PROCEDURE

Step	Check	Yes	No
1 CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR. Turn the ignition switch to OFF. Disconnect the connectors from ECM and front oxygen (A/F) sensor connector. Measure the resistance of harness between ECM and front oxygen (A/F) sensor connector. Connector & terminal (E158) No. 15 - (E24) No. 1: (E158) No. 27 - (E24) No. 4: (E158) No. 39 - (E24) No. 5:	Is the resistance less than 1 Ω?	Go to step 2 .	Repair the open circuit of harness between ECM and front oxygen (A/F) sensor 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 . >