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 Body Straight Line Dimensions (1) [Dimensions]
Point symbol Designation Hole diameter or bolt or nut size mm {in} A Cowl panel installation hole ?5 {0.2} B Wiper bracket datum hole ?7 {0.3} C ...

Speaker [With Bose®]
Purpose Converts the audio signal from the audio unit to sound. High quality sound is provided for the driver and passengers. Function Full-range speakers, which can output wide-range sound from low to high frequency, have been adopted. A better sound effect an ...

Auto Leveling Sensor
Purpose Detects the vehicle height and outputs it to the AFS control module. Function Changes the detected vehicle height into a voltage value and outputs it to the AFS control module. Construction Installed to the rear cross member. Consists of link No. 1 ...