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

WARNING: This page is about a different car, the 2006 Subaru Forester. However, it is still accessible from the selected car via links, so may be relevant.

DTC DETECTING CONDITION:

Immediately at fault recognition
GENERAL DESCRIPTION <Ref. to DTC P0134 O2 SENSOR CIRCUIT NO ACTIVITY DETECTED (BANK 1 SENSOR 1) , Diagnostic Trouble Code (DTC) Detecting Criteria. >

CAUTION: After repairing or replacing the defective part, carry out the Clear Memory Mode <Ref. to OPERATION , CLEAR MEMORY MODE. > and Inspection Mode <Ref. to PROCEDURE , INSPECTION MODE. >

WIRING DIAGRAM:

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

Courtesy of SUBARU OF AMERICA, INC.

TROUBLESHOOTING 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 the harness between ECM and front oxygen (A/F) sensor connector.