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.
- After servicing or replacing faulty parts, perform Clear Memory Mode Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>CLEAR MEMORY MODE>OPERATION , and inspection mode Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>INSPECTION MODE>PROCEDURE ..
- Use the check board when measuring the ECM terminal voltage and resistance.
Wiring diagram:
Engine Electrical System Refer to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM .
- CHECK HARNESS BETWEEN ECM AND REAR OXYGEN SENSOR CONNECTOR.
- Turn the ignition switch to OFF.
- Measure the voltage between ECM connector and engine ground.
Connector & terminal
(E159) No. 3 (+) - Engine 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.
- Disconnect the connector from ECM.
- Measure the resistance between the ECM connector and engine ground.
Connector & terminal
(B134) No. 35 - Engine ground:
(B134) No. 47 - Engine ground:
(E159) No. 10 - Engine ground:
(E159) No. 17 - Engine ground:
(E159) No. 18 - Engine ground:
(E159) No. 25 - Engine ground:
(E159) No. 26 - Engine ground:
Is the resistance less than 5 Ω?
Yes: Repair the poor contact of ECM connector.
No: Repair the harness and connector.
NOTE: In this case, repair the following item:- Open circuit of harness between ECM connector and engine ground
- Poor contact of coupling connector