Oxygen Sensor 2

Oxygen sensor activity is diagnosed once per trip.

Once the conditions for diagnosis are fulfilled, the sensor voltage changes and voltage level is measured. The sensor if defective if hhhhh sensor voltage does not change sufficiently to exceed a certain level within a certain time.

Fault criteria are fulfilled if the sensor voltage does not change more than 0.5 V or does not exceed 0.4 V for 500 sec. Otherwise, the sensor and its preheating is monitored according to OBD I for oxygen sensor 1.

Conditions for diagnosis
- Diagnosis not yet performed during this trip
- Engine running
- Vehicle speed above 0 km/h
- Coolant temperature above 70C (158F)
- Sensor preheating activated







1 Measure:
- sensor voltage
- time
2 Sensor voltage > 0.4 V and sensor voltage change > 0.5 V within 500 sec.
3 Diagnosis performed during this trip
4 Fault criteria for oxygen sensor 2, activity diagnosis fulfilled