Mazda CX-5 Service & Repair Manual: Heated Oxygen Sensor (HO2 S) Heater Control

Mazda CX-5 Service & Repair Manual / Engine / Control / Heated Oxygen Sensor (HO2 S) Heater Control

Outline

Based on the control of the HO2S 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

Operation

The PCM operates the HO2S heater based on the following control conditions.


Output duty ratio	Control condition
0%	Engine stopped Fuel cut injection control is in engine start zone Engine coolant temperature is -10 °C {14 °F}or less Other than battery voltage of 10—16 V Within a fixed period of time after engine start (varies according to engine coolant temperature)
30%	HO2S not activated
0?100% (Determined by engine speed and charging efficiency)	Other than the above

Engine Coolant Temperature (ECT) Sensor

Purpose/Function Detects the ECT as basic information for mainly determining the fuel injection amount. Detects the ECT and inputs it to the PCM as an ECT signal. The ECT sen ...

Heated Oxygen Sensor (HO2 S) Inspection

HO2S Inspection 1. Connect the M-MDS to the DLC?2. 2. Switch the ignition ON (engine on). 3. Warm up the engine to normal operating temperature. 4. Access the following PIDs using the M-MDS.. ...

Other materials:

Transfer Oil Replacement [Fw6 Ax EL]
1. Remove the front under cover No.2.. 2. Remove the drain plug with the washer. 3. Drain the oil into a suitable container. 4. Tighten the drain plug with a new washer. Tightening torque 40—58 N·m {4.1—5.9 kgf·m, 30—42 ft·lbf} 5. Remove the oil level plug with ...

Front Combination Light Removal/Installation
WARNING: Incorrect servicing of the discharge headlights could result in electrical shock. Before servicing the discharge headlights, always refer to the service warnings.. NOTE: Fogging or condensation on the inside of the front combination lights may occur due to a n ...

Battery [Skyactiv G 2.0]
Purpose, Function The battery stores electricity generated by the generator. In addition, it supplies power to electronic devices if necessary. Construction The battery is installed in the engine compartment. (vehicle left) Fail-safe Function not equipped. ...