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

WARNING: This page is about a different variant/trim than selected.

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 Rich 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. 46 - Chassis ground: (E158) No. 33 - 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 (E158) No. 33 (+) - 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 (E158) No. 46 (+) - Chassis ground (-): (E158) No. 33 (+) - 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.