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:

Towing Description
We recommend that towing be done only by an Authorized Mazda Dealer or a commercial tow-truck service. Proper lifting and towing are necessary to prevent damage to the vehicle. Particularly when towing a AWD vehicle, where all the wheels are connected to the drive train, proper transporting of ...

Controller Area Network (Can)
Outline The AWD control module (CM) sends and receives data to and from other modules via the CAN system. Refer to MULTIPLEX COMMUNICATION SYSTEM for a detailed explanation of the CAN system.. Data sent AWD system status Data received Engine speed Engin ...

Extractor Chamber Removal/Installation
1. Disconnect the negative battery cable.. 2. Remove the following parts: a. Rear splash shield. b. Rear combination light. c. Rear bumper. 3. Insert a tape-wrapped flathead screwdriver shown in the figure and remove clips in the direction of arrow (1). 4. Remove the extractor cham ...