AIR FUEL RATIO (A/F) SENSOR HEATER CONTROL [SKYACTIV-G 2.5 (WITH CYLINDER DEACTIVATION)]

id0140h1785500

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

ac5uun00003789

Operation

Normal control

• The PCM operates the A/F sensor 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 (value fluctuates by battery condition, etc.)

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 (value fluctuates by battery condition, etc.)