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:

Coupling Component Removal/Installation
WARNING: When replacing the coupling component, read the special character string before installing a new coupling component and write it to the AWD control module after replacement. The special character string is indicated in the two locations shown in the figure. 1. D ...

Shift Pressure Control (Line Pressure Control) [Fw6 A EL, Fw6 Ax EL]
Outline The TCM drives the pressure control solenoid and adjusts the pressure based on the accelerator pedal depression amount, vehicle speed, ATF temperature, and gear shift signal. As a result, line pressure is controlled finely and with high accuracy according to the engine load c ...

Mirrors
Mirrors Before driving, adjust the inside and outside mirrors. Outside Mirrors WARNING Be sure to look over your shoulder before changing lanes: Changing lanes without taking into account the actual distance of the vehicle in the convex mirror is dangerous. You could have a serious accident. ...