Mazda CX-5 Service & Repair Manual: Air Fuel Ratio (A/F) Sensor Heater Control [Skyactiv G 2.0]

Mazda CX-5 Service & Repair Manual / HVAC / General / Air Fuel Ratio (A/F) Sensor Heater Control [Skyactiv G 2.0]

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).
A pre-heater has been adopted to prevent water, produced from the exhaust system when the engine is started, from adhering to the sensor and damaging it.

Block Diagram

Operation

Pre-heater control

The A/F sensor heater is operated at a duty ratio of approx. 15% within the specified time directly after the engine is started.

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 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

Ignition switched off
Engine stopped
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.)

Air Filter Removal/Installation

1. Remove the glove compartment.. 2. Remove the air filter. 3. Install in the reverse order of removal. ...

Airflow Mode Main Link Removal/Installation

Full-auto Air Conditioner 1. The airflow mode main link is installed to the airflow mode actuator. When removing the airflow mode main link, refer to the airflow mode actuator removal/installation. ...

Other materials:

Front Lower Arm Inspection
1. Remove the front lower arm.. 2. Inspect the front lower arm for bending or damage, and the front lower arm ball joint for excessive looseness. If there is any malfunction, replace the front lower arm. 3. Rotate the front lower arm ball joint stud 5 times. Install the SST ...

Front Shock Absorber Disposal
WARNING: Whenever drilling into a front shock absorber, wear protective eye wear. The gas in the front shock absorber is pressurized, and could spray metal chips into the eyes and face when drilling. 1. Place the shock absorber on a level surface or with the piston pointing d ...

Outer Mirror Glass Removal
1. Disconnect the negative battery cable.. 2. Press area A of the outer mirror glass shown in the figure so that area B moves outward. 3. Put your hand on the lower part of the outer mirror glass and while supporting the hatch-marked area shown in the figure, remove pin C in the directio ...