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:

Heater Hose Removal/Installation
With Water Temperature Sensor 1. Remove the battery.. 2. Drain the engine coolant.. 3. Remove the insulator. 4. Remove the clips and remove the heater hose. 5. Remove the heater hose. 6. Install in the reverse order of the removal. 7. Inspect for engine coolant leaka ...

Cell Phones
Cell Phones Warning WARNING Please comply with the legal regulations concerning the use of communication equipment in vehicles in your country: Use of any electrical devices such as cell phones, computers, portable radios, vehicle navigation or other devices by the driver while the vehicle ...

Rear Seat Center Armrest Removal/Installation
1. Operate the push knob (RH) and lower the rear seat back (RH). 2. Remove screw A. 3. Remove the rear seat center armrest hinge cover (RH) in the direction of the arrow (1) shown in the figure while setting hook A aside. 4. Remove bolt B. 5. Remove the rear seat center armrest in ...