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:

Oil Pressure Switch Inspection
1. Switch the ignition ON (engine off) and verify that the oil pressure warning light is illuminated. 2. Start the engine and verify that the oil pressure warning light turns off. If the oil pressure warning light is not illuminated or remains illuminated, inspect the wiring harness ...

Heated Oxygen Sensor (HO2 S) Removal/Installation
WARNING: A hot engine and exhaust system can cause severe burns. Turn off the engine and wait until they are cool before removing the exhaust system. CAUTION: Do not allow flammable objects such as the taping for bundling wiring harness to come into contact with the exhau ...

PCM Removal/Installation
CAUTION: There are two types of PCM settings. If the incorrect PCM is installed, it could cause interference with engine control. When replacing the PCM, verify the first four digits of the part number indicated on the PCM label before replacement, and replace the PCM with one ...