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

Engine Electrical System ENGINE TYPE FA (WITHOUT PUSH BUTTON START) <Ref. to 2.0L TURBO (WITHOUT PUSH BUTTON START), WIRING DIAGRAM, Engine Electrical System.>
Engine Electrical System ENGINE TYPE FA (WITH PUSH BUTTON START) <Ref. to 2.0L TURBO (WITH PUSH BUTTON START), WIRING DIAGRAM, Engine Electrical System.>

Fig 1: O2 Sensor Circuit Diagram
Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTIC 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. Measure the resistance of harness between ECM connector and front oxygen (A/F) sensor connector. Connector & terminal E-150 No. 15 - (E24) No. 1: E-150 No. 27 - (E24) No. 4: E-150 No. 39 - (E24) No. 5:	Is the resistance less than 1 Ω?	Go to step 2 .	Repair the open circuit of harness between ECM connector 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 .>