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:

Power Window Regulator
Purpose The power window regulator moves the carrier plate up and down to open/close the door glass using the rotation force transmitted from the power window motor. Function The power window regulator transmits the rotation force from the power window motor to the inner wi ...

Front Wiring Harness Protector Removal/Installation
Front Wiring Harness Protector No.1 1. Disconnect the negative battery cable.. 2. Remove the air cleaner case.. 3. While pressing the tabs of clip A in the direction of the arrows (1) shown in the figure, pull clip A in the direction of the arrow (2) shown in the figure to detach the tab of ...

Power Brake Unit
Purpose/Function A 9.8-inch, single diaphragm type power brake unit has been adopted, achieving compatibility between high braking performance and excellent brake feeling. Construction The power brake unit cannot be disassembled. Therefore, if there is any malfunction in th ...