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

1. -

DTC detecting condition:

Detected when two consecutive driving cycles with fault occur.

Wiring diagram:

Engine Electrical System Ref. to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM .

G13626787

Courtesy of SUBARU OF AMERICA, INC.

CAUTION: Use the check board when measuring the ECM terminal voltage and resistance. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>GENERAL DESCRIPTION>PREPARATION TOOL>HOW TO USE CHECK BOARD .

NOTE: After the faulty parts are repaired or replaced, perform the final check in Basic Diagnostic Procedure. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE .

CHECK FRONT OXYGEN (A/F) SENSOR CONNECTOR AND COUPLING CONNECTOR .
1. Turn the ignition switch to OFF.
2. Check the front oxygen (A/F) sensor connector and coupling connector.
  Has water entered the connector?
  
  Yes : Completely remove any water inside.
  
  No : Go to 3 .
CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR (OPEN).
1. Disconnect the connector from ECM.
2. Disconnect the connector from the front oxygen (A/F) sensor.
3. Measure the resistance of harness between ECM connector and front oxygen (A/F) sensor connector.
  Connector and terminal
  
  (E53) No. 3 - (B94) No. 3:
  
  (E53) No. 4 - (B94) No. 4:
  
  Is the resistance less than 1 Ω?
  
  Yes : Go to 3.
  
  No : Repair the open circuit of harness between ECM connector and front oxygen (A/F) sensor connector.
CHECK FOR POOR CONTACT .
Check for poor contact of the front oxygen (A/F) sensor connector.

Is there poor contact of front oxygen (A/F) sensor connector?

Yes : Repair the poor contact of front oxygen (A/F) sensor connector.

No : Replace the front oxygen (A/F) sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FRONT OXYGEN (A/F) SENSOR .