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:

Fuel Filler Lid Opener And Lever Removal/Installation
Fuel-filler Lid Opener 1. Open the fuel-filler lid. 2. Remove the nut. 3. Remove the service hole cover on the trunk side trim. 4. While pressing the tabs of the stopper bracket in the direction of arrow (1) shown in the figure, press it in the direction of arrow (2) to detach it fr ...

Rear Mount Camera Inspection
1. Disconnect the negative battery cable.. 2. Remove the following parts: a. Liftgate upper trim. b. Liftgate side trim. c. Liftgate lower trim. d. Liftgate garnish. e. Rear mount camera. 3. Prepare four dry cell batteries (1.5 V) 4. Connect the four dry cell batteries in a series. ...

Magnet Clutch [Full Auto Air Conditioner]
Purpose The magnetic clutch transmits the rotation force from the engine to the shaft in the A/C compressor. Function The magnetic clutch engages or disengages the magnetic clutch and the A/C turns on or off by switching the power transmission from the engine. C ...