Front Oxygen Sensor (O2S 1)
DescriptionThe Powertrain Control Module (PCM) supplies a voltage of about 0.45 volts to the Oxygen Sensor 1 (O2S 1). The O2S 1 varies the voltage between a range of about 1 volt if the exhaust is rich, down through about 0.10 volt if the exhaust is lean.
The O2S 1 is like an open circuit and produces no voltage when the O2S 1 temperature is below 315°C (600°F). An open O2S 1 circuit or cold sensor causes "Open Loop" operation.