Fault Criteria, Oxygen Sensor 2 - Saab 9000 Service Manual

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Technical Description
Fault criteria, oxygen sensor 2
The oxygen sensor's activity is diagnosed once per
trip.
When the conditions for diagnosis are fulfilled, the
sensor's change in voltage and voltage level are
measured.
If sensor voltage does not change by a sufficient
amount and does not exceed a certain level within a
certain time, the sensor is defective.
If sensor voltage does not change by more than 0.5
V and does not exceed 0.4 Vin 500 seconds, the fault
criteria are satisfied.
V
0.8
0.6
0.4
0.2
0.0
In other respects the sensor and its heating element
are monitored according to the On-BoardDiagnostic
I model for the front heated oxygen sensor.
Conditions for diagnosis
• Diagnosis not yet performed this trip
• Engine running
• Vehicle speed above O mph (0 km/h)
• Coolant temperature above 70°C (158°F)
• Sensor heating activated
OX2
0 10 20 30 40 50 60 70 80 90 100
@ s
Saab 9000