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:

Discharge Headlight Control Module 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.. 1. Disconnect the negative battery cable.. 2. Remove the front bumper.. 3. Disconnect the connector. ...

Exhaust Gas Purification System
Purpose, Outline Purifies contaminants (HC, CO, NOx) in the exhaust gas by utilizing the chemical reactions of the three-way catalytic converter. System Diagram Structure The exhaust gas purification system consists of the following parts: Par ...

Power Windows
The ignition must be switched ON for the power windows to operate. WARNING Make sure the opening is clear before closing a window: Closing power windows are dangerous. A person's hands, head, or even neck could be caught by the window and result in serious injury or even death. This warning ...