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DTC P0134: A/F/O2 Sensor Circuit No Activity Detected Bank 1 Sensor 1: Notes

1. -

DTC detecting condition:

Immediately at fault recognition

Wiring diagram:

Engine Electrical System. Refer 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. Refer 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. Refer to ENGINE (Diagnostics) (H4DO)>Basic Diagnostic Procedure>PROCEDURE .

CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR (OPEN) .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Disconnect the connector from the front oxygen (A/F) sensor.
4. Measure the resistance of harness between ECM connector and front oxygen (A/F) sensor connector.
  Connector & terminal
  
  (E53) No. 3 - (B94) No. 3:
  
  (E53) No. 4 - (B94) No. 4:
Is the resistance less than 1 Ω?

Yes : Go to 2.

No : Repair the following item.
- Open circuit in harness between ECM connector and front oxygen (A/F) sensor connector
- Poor contact of coupling connector
CHECK FOR POOR CONTACT .
Check for poor contact of ECM and front oxygen (A/F) sensor connector. Is there poor contact of ECM or front oxygen (A/F) sensor connector?

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

No : Replace the front oxygen (A/F) sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>Front Oxygen (A/F) Sensor .