AIR FUEL RATIO (A/F) SENSOR HEATER CONTROL [SKYACTIV-D 1.5]

id0140z5785500

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

am2zzn00003736

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