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

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

Engine Electrical System ENGINE TYPE EJ (WITHOUT PUSH BUTTON START) Ref. to the appropriate SYSTEM WIRING diagram article. ENGINE TYPE EJ (WITHOUT PUSH BUTTON START).
Engine Electrical System ENGINE TYPE EJ (WITH PUSH BUTTON START) Ref. to the appropriate SYSTEM WIRING diagram article. ENGINE TYPE EJ (WITH PUSH BUTTON START).

Fig 1: Engine Electrical System - Wiring Diagram (Engine Type EJ)
Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTIC 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 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.