V70 GL L5-2.4L VIN 55 B5254S (1998)
Both heated oxygen sensor (HO2S) terminals are connected to the engine control module (ECM).
When the engine is running rich, the oxygen content of the exhaust gases is low or zero. The heated oxygen sensor (HO2S) is then transmitting an
output voltage of approx. 0.9 V.
When the engine is running lean, there is an excess of oxygen in the exhaust gases. The output voltage from the heated oxygen sensor (HO2S) almost
drops to 0 V.
The change from high to low signal level occurs at the ideal (stoichiometric) air/fuel ratio of 14.7 kg air/1 kg fuel.
The engine control module (ECM) continuously uses the heated oxygen sensor (HO2S) signal to control fuel injection so as to maintain the ideal
air/fuel ratio of 14.7 kg air/1 kg fuel.
