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:

Front Door Hinge Removal/Installation
1. Disconnect the negative battery cable.. 2. Remove the following parts: a. Front bumper. b. Front combination light. c. Front bumper slider. d. Front over fender. e. Front fender panel. f. Front door. 3. Remove in the order shown in the figure. 1 Bolt ...

Liftgate Recess Removal/Installation
1. Insert a tape-wrapped flathead screwdriver in the position indicated by the arrow in the figure and detach hooks A. 2. Remove the liftgate recess in the direction of the arrow shown in the figure avoiding hooks B. 3. Install in the reverse order of removal. ...

Power Window System Preliminary Inspection [Power Window System]
Manual Open/Close Function Inspection STEP INSPECTION ACTION 1 Switch the ignition ON (engine off or on). Operate the power window using the manual open/close function on the power window main swit ...