9-3 (9440) L4-2.0L Turbo (2.0 HOT) (2003)
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To quickly yield voltage after start, the oxygen sensor must be preheated. Grounding of the preheating circuit is pulse width modulated so that preheating
output can be regulated.
Preheating is activated as soon as coolant temperature exceeds 30 degree C.
The control module estimates exhaust temperature based on load and engine speed. If exhaust temperature is high, preheating is switched off so as not to
damage the oxygen sensor.
If the catalytic converter is damaged, its ability to store oxygen decreases. The normal oscillations of closed loop will then be detected based on the
