AIR FUEL RATIO (A/F) SENSOR HEATER CONTROL [WITHOUT CYLINDER DEACTIVATION (SKYACTIV-G 2.0, SKYACTIV-G 2.5)]

id0140m1785500

Outline

• Based on the control of the A/F sensor 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

ac5wzn00005555

Operation

Normal control

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

Output duty ratio

Control condition

0 %

When any of the following conditions is met

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