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

id0140i7782200

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.

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.