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DTC P0038: A/F/O2 Heater Control Circuit High Bank 1 Sensor 2: Notes

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 ENGINE (DIAGNOSTICS) (H4DO)>CLEAR MEMORY MODE>OPERATION ., and inspection mode Ref. to ENGINE (DIAGNOSTICS) (H4DO)>INSPECTION MODE>PROCEDURE .
Use the check board when measuring the ECM terminal voltage and resistance.

Wiring diagram:

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

G12409960

Courtesy of SUBARU OF AMERICA, INC.

CHECK HARNESS BETWEEN ECM AND REAR OXYGEN SENSOR CONNECTOR .
1. Turn the ignition switch to OFF.
2. Measure the voltage between ECM connector and chassis ground.
  Connector & terminal
  
  (E158) No. 10 (+) - Chassis ground (-):
Is the voltage 10 V or more?

Yes: Repair the short circuit to power in the harness between ECM connector and rear oxygen sensor connector.

No: Go to 2 .
CHECK GROUND CIRCUIT FOR ECM .
1. Disconnect the connector from ECM.
2. Measure the resistance between ECM connector and chassis ground.
  Connector & terminal
  
  (E158) No. 61 - Chassis ground:
  
  (E158) No. 62 - Chassis ground:
  
  (E158) No. 63 - Chassis ground:
  
  (E158) No. 64 - Chassis ground:
  
  (E158) No. 65 - Chassis ground:
Is the resistance less than 5 Ω?

Yes: Repair the poor contact of ECM connector.

No: Repair the open circuit in harness between ECM connector and engine ground.