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:

Drive Belt
Purpose, Function The drive belt transmits rotation force of the crankshaft pulley to the pulley for the auxiliary parts. Construction The drive belt is installed to the front of the engine. A V-ribbed belt has been adopted for the drive belt. The wat ...

Purge Solenoid Valve
Purpose, Function Introduces evaporative gas absorbed by the charcoal canister to the intake manifold. The purge solenoid valve opens according to the control signal from the PCM. Construction The purge solenoid valve is installed in the engine compartment. ...

Shroud Side Member Removal [Panel Replacement]
Symbol Mark Removal Procedure 1. Drill the 3 locations indicated by (A) shown in the figure. 2. Drill the 8 locations indicated by (B) and 2 locations indicated by (C) shown in the figure. NOTE: When drilling the 3 locations indicated by (A) and 2 locations indicated by (C) sh ...