DTC P2196 A/F/O2 Sensor Signal Biased/Stuck Rich Bank 1 Sensor 1: Notes

DTC DETECTING CONDITION:

Detected when two consecutive driving cycles with fault occur.

CAUTION:

After servicing or replacing faulty parts, perform Clear Memory Mode <Ref. to OPERATION , Clear Memory Mode.>, and Inspection Mode <Ref. to PROCEDURE , Inspection Mode.>.
Use the check board when measuring the ECM terminal voltage and resistance.

WIRING DIAGRAM:

Engine Electrical System <Ref. to WIRING DIAGRAM , Engine Electrical System.>

Fig 1: A/F /O2 Sensor Signal Biased/Stuck Lean Bank 1 Sensor 1 - Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

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 connector 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 short circuit to ground in harness between ECM connector 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 connector 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 connector and front oxygen (A/F) sensor connector.	Repair the poor contact of ECM connector.