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:

Afs Off Indicator Light
Purpose The AFS OFF indicator light notifies the user that the AFS is stopped or a malfunction occurs in the AFS. Function The AFS OFF indicator light illuminates when the AFS is stopped and flashes when a malfunction occurs in the AFS. Construction When the mi ...

Steering Gear And Linkage Inspection
1. Remove the steering gear and linkage.. 2. Remove the tie-rod end and boot.. 3. Measure the rotation torque of the pinion shaft using a crescent wrench and pull scale. (speed measurement reference 5 В°/s) a. Install the crescent wrench to the steering gear. b. Measure the length fr ...

Fan Switch Inspection [Manual Air Conditioner]
1. Disconnect the negative battery cable.. 2. Remove the following parts: a. Shift lever knob (MTX). b. Glove compartment. c. Front console box. d. Shift panel. e. Upper panel. f. Rear console. g. Side wall. h. Decoration panel. i. Front console. 3. Remove the climate control u ...