HEATED OXYGEN SENSOR (HO2S) HEATER CONTROL [SKYACTIV-X 2.0]

id0140hf785600

Outline

• Based on the control of the HO2S heater, a stabilized oxygen concentration is detected even at low exhaust temperatures, and feedback control of fuel injection even at cold engine start is made possible for improved cold temperature exhaust emission performance.

• Both emission performance and sensor protection have been improved by duty control of the heater according to engine operation conditions (exhaust gas temperature)

Block Diagram

atsuzn00001020

Operation

• The PCM operates the HO2S heater based on the following control conditions.

Output duty ratio

Control condition

0%

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

•  Fuel cut injection control is in engine start zone

•  Engine coolant temperature is -10 °C {14 °F}or less

•  Other than battery voltage of 9—16 V

•  Within a fixed period of time after engine start (varies according to engine coolant temperature)

0―100%

(Duty ratio determined by measuring the element temperature by the HO2S sensor heater element impedance)

•  After engine warm-up (value fluctuates by battery condition, etc.)

Output duty ratio	Control condition
0%	• Engine stopped (excludes engine stop by i-stop control) • Fuel cut injection control is in engine start zone • Engine coolant temperature is -10 °C {14 °F}or less • Other than battery voltage of 9—16 V • Within a fixed period of time after engine start (varies according to engine coolant temperature)
0―100% (Duty ratio determined by measuring the element temperature by the HO2S sensor heater element impedance)	• After engine warm-up (value fluctuates by battery condition, etc.)