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:

Awd Control Module
Purpose, Function The AWD CM calculates the optimal amount of torque distribution for the rear wheels and outputs a corresponding electric current to the electronic control coupling (AWD solenoid). This calculation is based on the accelerator pedal angle, four-wheel speed, engine spe ...

Master Cylinder Removal/Installation
1. Remove the battery.. 2. Remove in the order indicated in the table. 3. Install in the reverse order of removal. 4. After installation, add brake fluid, bleed the air, and inspect for fluid leakage.. 1 Brake fluid level sensor connector 2 ...

Steps for Determining the Correct Load Limit
Steps for Determining Correct Load Limit- (1) Locate the statement “The combined weight of occupants and cargo should never exceed XXX kg or XXX lbs” on your vehicle's placard. (2) Determine the combined weight of the driver and passengers that will be riding in your vehicle. (3) Subt ...