Upstream oxygen sensors can have two types of malfunction:
- mechanical failure in the electrical part (breakdown, wire breakage), which leads to a malfunction in the electrical circuit;
- deterioration of chemical characteristics, which leads to an increase in the response time of the sensor, and, consequently, to an increase in its response period.
After the test conditions have been met, the obtained sensor periods are averaged (discarding parasitic effects) and compared with the average threshold period included in the on-board diagnostics system.
Test conditions
Upstream oxygen sensor diagnostics can only be performed if the pre-ignition conditions are met and are being met.
- no electrical faults;
- programming done;
- no misfires detected;
- coolant temperature above 40°C;
- the average engine crankshaft speed is within 650-6200 min⁻¹;
- engine load does not matter;
- the speed of movement does not matter.
Troubleshooting
The diagnostics are performed by the customer during the trip in accordance with the conditions described above, with the canister purge prohibited. The ECU issues the indication "oxygen sensor diagnostics: completed".
Caution! At the end of this test, do not turn off the ignition under any circumstances before reading the result on the diagnostic tool. Turning off the ignition will result in incorrect interpretation of the results.
Confirmation of repair
Oxygen sensor on-board diagnostics: "ACTIVELY COMPLETED".
Oxygen sensor fault: "INACTIVE".
Oxygen sensor repair confirmation: "YES".
[Original article is on the portal RenaultBook]
If the diagnostic tool displays O2 Sensor On-Board Diagnostic: "completed. ACTIVE" or "O2 Sensor Repair Confirmed. 1DEF", the test cycle has not been performed correctly. In this case, repeat the test cycle strictly observing the diagnostic conditions.
If the diagnostic tool displays the message "Catalytic Converter Malfunction. ACTIF" or "Oxygen Sensor Repair Confirmation. 2DEF" after the test, refer to the diagnostic method corresponding to the malfunction.