It is performed by measuring and comparing the response times of oxygen sensors.
There are two types of possible upstream oxygen sensor failures:
- mechanical failure of one of the electrical components (breakage, broken wire), which is classified as an electrical fault;
- chemical failure of the component, which leads to an increase in the response time of the sensor, and, consequently, to an increase in the period of its operation.
After the test conditions are met, the obtained sensor periods are averaged (discarding parasitic effects) and compared with the average threshold period «OVO».
Test conditions
Upstream oxygen sensor diagnostics can only be performed after the engine has been running for 15 minutes. if the conditions prior to switching on the ignition are met and fulfilled.
- no electrical faults;
- programming and cylinder recognition completed;
- since the ignition was switched on, the oxygen sensor diagnostics were not performed;
- no mixture misfires detected;
- coolant temperature above 75°C;
- the average engine crankshaft speed is within 1824-4000 min' for the F4P engine and 1632-4000 min' for the K4M engine;
- pressure is in the range of 328-750 mbar;
- the car is moving at a speed of 63-130 km/h,
Troubleshooting
Diagnosis is carried out by the customer during the trip in accordance with the conditions described above, with the purging and emptying of the absorber prohibited. This test is performed for at least 40 s. The ECU issues an instruction - oxygen sensor diagnosis: in progress».
The duration of the test cannot exceed 52 s without exiting the loop.
Attention! At the end of this test, never switch off the ignition before reading the result on the scan tool. Switching off the ignition leads to incorrect interpretation of the results.
Repair Confirmation
Issue a command «Oxygen sensor diagnostics using the on-board diagnostics system is performed»: «ACTIVELY».
Diagnostics of the oxygen sensor using the on-board diagnostics system is performed: «ACTIVELY».
Malfunction of the oxygen sensor: «NOT ACTIVE».
Oxygen sensor repair confirmation: «YES».
If the scan tool displays OBD OBD Diagnostic: Passed. ACTIVELY» or «Oxygen sensor repair confirmation. 1 DEF», then the control cycle was executed incorrectly. In this case, repeat the control cycle under strict observance of the diagnostic conditions.
If a message appears on the scan tool screen after the test «Malfunction in the operation of the catalytic converter. ACTIVELY» or «Oxygen sensor repair confirmation. 2DEF», refer to the diagnostic method of the corresponding fault.