DTC P0139: HO2S Slow Response Sensor 2: Troubleshooting
TROUBLESHOOTING CHART
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| 1 | Perform an On-Board Diagnostic (OBD) System Check. Is the system check complete? |
- | Go to Step 2 | Go to On-Board Diagnostic (OBD II) System Check |
| 2 |
Does the scan tool indicate the Closed Loop? |
- | Go to Step 3 | Go to Step 4 |
| 3 |
Does the scan tool indicate the Closed Loop? |
- | Go to Step 12 | Go to Step 4 |
| 4 |
Does the scan tool read the oxygen sensor signal voltage the specified value? |
0.4 - 0.5 V | Go to Step 5 | Go to Step 8 |
| 5 | Check the oxygen sensor connector for malfunction terminals or poor connection and repair as necessary. Is repair necessary? |
- | Go to Step 12 | Go to Step 6 |
| 6 |
Does the oxygen sensor voltage measure above the specified value? |
0.6 V | Go to Step 7 | Go to Step 11 |
| 7 |
Does the oxygen sensor voltage measure above the specified value? |
0.3 V | Go to Step 9 | Go to Step 11 |
| 8 | Repair the wire or the connector between the HO2S terminal 3 and the Engine Control Module (ECM) terminal C4 is open or a short to ground. Is the repair complete? |
- | Go to Step 11 | Go to Step 9 |
| 9 | Repair the wire and the connector terminal between the oxygen sensor connector terminal 4 and the ECM connector terminal C57 is open or a short to ground. Is the repair complete? |
- | Go to Step 12 | Go to Step 10 |
| 10 |
Is the repair complete? |
- | System OK | - |
| 11 | Replace the O2 sensor. Is the repair complete? |
- | Go to Step 12 | - |
| 12 |
Is the repair complete? |
- | Go to Step 13 | - |
| 13 | Check if any additional DTCs are set. Are any DTCs displaced that have not been diagnosed? |
- | Go to applicable DTC table | System OK |