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:

Fuel Filler Cap Inspection
Leakage Inspection 1. Perform the following tester (evaporative emission system tester (134-01049A)) self-test: NOTE: If the tester does not work correctly during self-test, refer to the tester operators manual for more detailed procedures. a. Verify that the gas cylinder valve ...

Audio Control Switch Operation
When the audio unit is turned on, operation of the audio unit from the steering wheel is possible. NOTE Because the audio unit will be turned off under the following conditions, the switches will be inoperable. • When the ignition is switched off. • When the power button on the audio uni ...

Filament Repair
1. Clean the filament using isopropyl alcohol. 2. Attach tape to both sides of the filament. 3. Using a small brush or marking pen, apply silver paint. 4. After 2—3 min, carefully remove the tape without damaging the applied area. CAUTION: Do not operate the rear window defro ...