DTC P0139 O2 Sensor Circuit Slow Response (Bank 1 Sensor 2)
DTC DETECTING CONDITION:
- Two consecutive driving cycles with fault
- GENERAL DESCRIPTION < Ref. to DTC P0139 O2 SENSOR CIRCUIT SLOW RESPONSE (BANK 1 SENSOR 2) , Diagnostic Trouble Code (DTC) Detecting Criteria. >
CAUTION:
After repairing or replacing the defective part, perform the Clear Memory Mode < Ref. to
OPERATION , Clear Memory Mode. > and Inspection Mode < Ref. to
PROCEDURE , Inspection Mode. >.
WIRING DIAGRAM:
DIAGNOSTIC PROCEDURE
| Step | Check | Yes | No |
|---|---|---|---|
| 1 CHECK ANY OTHER DTC ON DISPLAY. | Is any other DTC displayed? | Check DTC using "List of Diagnostic Trouble Code (DTC)". < Ref. to
LIST OF DIAGNOSTIC TROUBLE CODE (DTC) . >
NOTE:
In this case, it is not necessary to inspect DTC P0139.
|
Go to step 2. |
2 CHECK HARNESS BETWEEN ECM AND REAR OXYGEN SENSOR CONNECTOR.
|
Is the resistance less than 1 Ω? | Go to step 3. | Repair the open circuit of harness between ECM and rear oxygen sensor connector. |
| 3 CHECK HARNESS BETWEEN ECM AND REAR OXYGEN SENSOR CONNECTOR. Measure the resistance between rear oxygen sensor harness connector and chassis ground. Connector & terminal (T6) No. 4 - Chassis ground: |
Is the resistance more than 1 MΩ? | Go to step 4. | Repair the chassis short circuit of harness. |
| 4 CHECK REAR OXYGEN SENSOR. Measure the resistance between rear oxygen sensor terminals. Terminals No. 3 - No. 4: |
Is the resistance less than 1 Ω? | Replace the rear oxygen sensor. < Ref. to REAR OXYGEN SENSOR . > | Temporary poor contact occurs. Check the poor contact of connector. |