AIR FUEL RATIO (A/F) SENSOR, HEATED OXYGEN SENSOR (HO2S) HEATER CONTROL OPERATION [L8, LF]

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Operation Conditions

• The PCM operates the A/F sensor or HO2S when the following conditions are met.

Item | Activation condition | Drive signal
--- | --- | ---
A/F sensor | • After engine start • After the engine has started and a fixed period of time has elapsed (the elapsed time period after the engine starts is determined by ECT). • ECT is –10 °C {14 °F} or more. • Battery positive voltage is 9 V or more and less than 16 V. • MAF sensor is normal (no DTC is stored in PCM). | • The PCM outputs a duty signal. • The element temperature is measured by the impedance of the A/F sensor and a duty ratio is determined.
HO2S | • Starter is off • After engine start • After the engine has started and a fixed period of time has elapsed (the time period after the engine starts lengthen if the ECT falls below 0°C {32°F}. • ECT is –10 °C {14 °F} or more. • Battery positive voltage is 9 V or more and less than 16 V. • Charging efficiency is the fixed value or less, or during fuel cut. | • The PCM outputs a duty signal.