Mazda CX-5 Service & Repair Manual: Heated Oxygen Sensor (HO2 S) Heater Control [Skyactiv G 2.0]

Mazda CX-5 Service & Repair Manual / HVAC / General / Heated Oxygen Sensor (HO2 S) Heater Control [Skyactiv G 2.0]

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

Front Heat Duct Removal/Installation

1. Disconnect the negative battery cable.. 2. Remove the following parts: a. Dashboard under cover. b. Side wall. c. Glove compartment. 3. Detach the tab and remove the front heat duct. LH ...

Heater Core

Purpose The heater core heats passing air. Function A portion of the engine coolant is taken into the heater core to heat the air passing through the heater core. Co ...

Other materials:

Front Map Light
Purpose The front map lights shine light at the front of the vehicle interior. Function The front map lights illuminate when the map light switch is turned on. Illuminates according to the lock condition of the driver's door and open/close conditions of the doors u ...

Lights On Indicator Light
Purpose Notifies the user that the TNS or the headlights (LO) are on. Function Illuminates when the illumination conditions for the TNS, headlights (LO), or parking lights are met. When the instrument cluster receives the TNS malfunction signal sent via CAN communic ...

Refrigerant Pressure Check
NOTE: Measure the refrigerant pressure after approx.10 min have elapsed from engine start. 1. Install the manifold gauge.. 2. Start the engine and warm it up. 3. Set the fan speed MAX HI. 4. Turn the A/C switch on. 5. Set to RECIRCULATE mode. 6. Set the temperature control ...