AIR FUEL RATIO (A/F) SENSOR HEATER CONTROL [SKYACTIV-G 1.5, SKYACTIV-G 2.0]

id0140g8785500

Outline

• Performs duty control of the heater according to the engine operation conditions (exhaust gas temperature) for A/F sensor protection and enhanced emission performance.

• By controlling the A/F sensor heater, stable detection of oxygen concentration is possible even with low exhaust gas temperature, and feedback control for the fuel injection control is possible even after cold engine start, enhancing the emission performance under cold temperatures.

Block Diagram

amxzzn00001960

Operation

Normal control

• The PCM operates the A/F sensor heater based on the following control conditions:

Output duty ratio

Control condition

0 %

•  Ignition switched off

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

•  Engine start (cranking)

0―100 %

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

•  After engine warm-up (such as value fluctuates by battery condition)

Output duty ratio	Control condition
0 %	• Ignition switched off • Engine stopped (excludes engine stop by i-stop control) • Engine start (cranking)
0―100 % (Duty ratio determined by measuring the element temperature by the A/F sensor heater element impedance)	• After engine warm-up (such as value fluctuates by battery condition)