DTC P0154 O2 Sensor Circuit No Activity Detected (Bank 2 Sensor 1)

DTC DETECTING CONDITION:

Immediately at fault recognition
GENERAL DESCRIPTION < Refer to DTC P0154 O2 SENSOR CIRCUIT NO ACTIVITY DETECTED (BANK 2 SENSOR 1) , Diagnostic Trouble Code (DTC) Detecting Criteria. >

CAUTION: After repair or replacement of faulty parts, perform Clear Memory Mode < Refer to OPERATION , CLEAR MEMORY MODE > and inspection Mode < Refer to PROCEDURE , INSPECTION MODE >.

WIRING DIAGRAM:

Fig 1: Heated Front Oxygen Sensor - Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTIC 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. 10 - (E24) No. 4: (B135) No. 11- (E24) No. 3:	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 of harness between ECM and front oxygen (A/F) sensor connector Poor contact in front oxygen (A/F) sensor connector Poor contact in ECM connector
2 CHECK POOR CONTACT. Check poor contact of front oxygen (A/F) sensor connector.	Is there poor contact in front oxygen (A/F) sensor connector?	Repair the poor contact in front oxygen (A/F) sensor connector.	Replace the front oxygen (A/F) sensor. < Refer to FRONT OXYGEN (A/F) SENSOR . >