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.>.

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 (B136) No. 18 - Chassis ground: (B136) No. 19 - 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 OUTPUT SIGNAL FOR ECM. Connect the connector to ECM. Turn the ignition switch to ON. Measure the voltage between ECM connector and chassis ground. Connector & terminal (B136) No. 19 (+) - Chassis ground (-):	Is the voltage 4.5 V or more?	Go to step 5.	Go to step 4.
4 CHECK OUTPUT SIGNAL FOR ECM. Measure the voltage between ECM connector and chassis ground. Connector & terminal (B136) No. 18 (+) - Chassis ground (-):	Is the voltage 4.95 V or more?	Go to step 5.	Replace the front oxygen (A/F) sensor. <Ref. to Front Oxygen (A/F) Sensor .>
5 CHECK OUTPUT SIGNAL FOR ECM. Measure the voltage between ECM connector and chassis ground. Connector & terminal (B136) No. 18 (+) - Chassis ground (-): (B136) No. 19 (+) - 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. After repair, replace the ECM. <Ref. to Engine Control Module (ECM) .>	Repair the poor contact of ECM connector.