DTC P2196: O2 Sensor Signal Biased/Stuck Rich (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 FRONT OXYGEN (A/F) SENSOR CONNECTOR AND COUPLING CONNECTOR.	Has water entered the connector?	Completely remove any water inside.	Go to step 2 .
2 CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR. Turn the ignition switch to OFF. Disconnect the connector from ECM. Measure the resistance between ECM and chassis ground. Connector & terminal (E158) No. 15 - Chassis ground: (E158) No. 27 - Chassis ground: (E158) No. 39 - Chassis ground:	Is the resistance 1 MΩ or more?	Go to step 3 .	Repair the ground short circuit of harness between ECM and front oxygen (A/F) sensor connector.
3 CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR. Connect the connector to ECM. Disconnect the connectors from front oxygen (A/F) sensor. Turn the ignition switch to ON. Measure the voltage between ECM and chassis ground. Connector & terminal (E158) No. 15 (+) - Chassis ground (-): (E158) No. 27 (+) - Chassis ground (-): (E158) No. 39 (+) - Chassis ground (-):	Is the voltage 8 V or more?	Repair the short circuit to power in the harness between ECM and front oxygen (A/F) sensor connector.	Repair the poor contact of ECM connector.