AIR FUEL RATIO (A/F) SENSOR HEATER CONTROL [SKYACTIV-D 2.2]

id0140z7785500

Outline

• By activating the A/F sensor using the A/F sensor heater, stable detection of the oxygen concentration is possible even when the exhaust gas temperature is low.

• When the exhaust gas temperature is high, enerzation to the A/F sensor heater is stopped to protect the A/F sensor from a rise in temperature.

Block diagram

ac5wzn00002131

Operation

• The PCM operates the A/F sensor heater when the following control conditions are met:

Output duty value

Control conditions

0 %

When any of the following conditions is met

•  Ignition is switched off

•  Engine is stopped (excludes engine stop by i-stop control)

•  Engine is being started (cranking)

0―100 %

(Duty ratio determined by measuring the element temperature from the A/F sensor heater element impedance)

When the following conditions are all met

•  Engine is started and a certain period of time has elapsed (elapsed time after engine start is calculated based on exhaust gas temperature)

•  Battery voltage: 9—16 V

Output duty value	Control conditions
0 %	When any of the following conditions is met • Ignition is switched off • Engine is stopped (excludes engine stop by i-stop control) • Engine is being started (cranking)
0―100 % (Duty ratio determined by measuring the element temperature from the A/F sensor heater element impedance)	When the following conditions are all met • Engine is started and a certain period of time has elapsed (elapsed time after engine start is calculated based on exhaust gas temperature) • Battery voltage: 9—16 V