HEATED OXYGEN SENSOR (HO2S) HEATER CONTROL [WITHOUT CYLINDER DEACTIVATION (SKYACTIV-G 2.0, SKYACTIV-G 2.5)]

id0140m1785600

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

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Operation

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

Without coolant control valve

Output duty ratio

Control condition

0 %

When any of the following conditions is met

•  Engine stopped

•  Fuel cut injection control is in engine start zone

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

•  Other than battery voltage of 10—16 V

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

30―50 %

•  HO2S not activated

0―100 %

(Determined by engine speed and charging efficiency)

•  Other than the above

Output duty ratio	Control condition
0 %	When any of the following conditions is met • Engine stopped • Fuel cut injection control is in engine start zone • Engine coolant temperature is −10 °C {14 °F} or less • Other than battery voltage of 10—16 V • Within a fixed period of time after engine start (varies according to engine coolant temperature)
30―50 %	• HO2S not activated
0―100 % (Determined by engine speed and charging efficiency)	• Other than the above

With coolant control valve

Output duty ratio

Control condition

0%

When any of the following conditions is met

•  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%	When any of the following conditions is met • 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.)