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:

Clock Removal/Installation
1. Disconnect the negative battery cable.. 2. Remove the following parts: a. Shift lever knob (MTX). b. Front console box. c. Shift panel. d. Upper panel. e. Rear console. f. Side wall. g. Decoration panel. h. Front console. i. Glove compartment. j. Climate control unit. 3. P ...

Clock
The time is displayed when the ignition is switched to ACC or ON. With Fully Automatic Type Climate Control System With Manual Type Climate Control System Time setting 1. Switch the ignition ACC or ON. 2. Adjust the time using the time setting buttons ( , ). The hours advance while the t ...

Power Window Motor Inspection
Front driver side 1. Disconnect the negative battery cable.. 2. Remove the inner garnish.. 3. Remove the front door trim.. 4. Disconnect the power window motor connector. 5. Apply battery positive voltage and connect the ground to power window motor terminals E and F, and then inspect the ...