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

Fig 1: O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1) - Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSIS PROCEDURE CHART

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 and front oxygen (A/F) sensor connector. Measure the resistance of harness between ECM and front oxygen (A/F) sensor connector. Connector & terminal  (B135) No. 8 - (B262) No. 3:  (B135) No. 9 - (B262) No. 4:	Is the resistance less than 1 Ω?	Replace the front oxygen (A/F) sensor. <Ref. to FRONT OXYGEN (A/F) SENSOR . >	Repair the open circuit of harness between ECM and front oxygen (A/F) sensor connector.