DTC P0130: A/F/O2 Sensor Circuit Bank 1 Sensor 1: Notes

DTC detecting condition:

Immediately at fault recognition

CAUTION: Use the check board when measuring the ECM terminal voltage and resistance. Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>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) (H4DOTC)>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE .

Wiring diagram:

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

Courtesy of SUBARU OF AMERICA, INC.

CHECK FRONT OXYGEN (A/F) SENSOR DATA .
1. Start the engine and warm up until the engine coolant temperature exceeds 75°C (167°F).
2. Idle the engine for one minute or more.
3. Using the Subaru Select Monitor, read the value in [A/F Sensor #11].
NOTE: For detailed operation procedures, refer to "COMMON (DIAGNOSTICS)". Ref. to COMMON (DIAGNOSTICS)>DATA MONITOR .

Is the value of [A/F Sensor #11] 1.2 - 3 [V]?

Yes: Go to 2.

No: Go to 3.
CHECK FRONT OXYGEN (A/F) SENSOR DATA .
1. Race the engine so that the engine speed stays at 3000 RPM. (Five times in total)
2. Using the Subaru Select Monitor, read the value of [A/F Sensor #11] during racing.
NOTE:
- Slowly depress the accelerator pedal to increase engine speed up to 3000 RPM, keep it for approximately 5 seconds, and quickly release the accelerator pedal to decrease engine speed.
- Normally, the air fuel ratio is rich during racing.
- For detailed operation procedures, refer to "COMMON (DIAGNOSTICS)". Ref. to COMMON (DIAGNOSTICS)>DATA MONITOR .
Is the value of [A/F Sensor #11] 2.5 [V] or more?

Yes: Go to 5.

No: Go to 3.
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
  
  (E51) No. 52 - (E76) No. 1:
  
  (E51) No. 51 - (E76) No. 4:
  
  (E51) No. 53 - (E76) No. 5:
Is the resistance less than 1 Ω?

Yes: Go to 4.

No: Repair the open circuit of harness between ECM connector and front oxygen (A/F) sensor connector.
CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR (SHORT TO GROUND) .
Measure the resistance between the ECM connector and engine ground.

Connector & terminal

(E51) No. 52 - Engine ground:

(E51) No. 51 - Engine ground:

(E51) No. 53 - Engine ground:

Is the resistance 1 MΩ or more?

Yes: Go to 5.

No: Repair the short circuit to ground in harness between ECM connector and front oxygen (A/F) sensor connector.
CHECK EXHAUST SYSTEM .
Check exhaust system parts.
NOTE:
Check the following items.
- Looseness and improper fitting of exhaust system parts
- Damage (crack, hole etc.) of parts
- Loose or improperly attached front oxygen (A/F) sensor and rear oxygen sensor
Is there any fault in exhaust system?

Yes: Repair or replace faulty parts.

No: Replace the front oxygen (A/F) sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DOTC)>FRONT OXYGEN (A/F) SENSOR .