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:

Hood
Purpose/Function The hood is constructed with a large space between the front end of the hood and the engine to absorb an impact. Construction The hood stiffener positioned at the front end of the hood is shaped so that it collapses easily during an impact. In addition, the ...

TCM [Fw6 A EL, Fw6 Ax EL]
Purpose/Function The TCM detects the vehicle conditions and performs calculations and processing based on input information from each type of sensor and switch. Outputs control signals to each solenoid valve so that each type of control is optimally implemented according to the ...

Positive Crankcase Ventilation (PCV) Valve Inspection
Airflow Inspection 1. Disconnect the section (A) of ventilation hose shown in the figure. 2. Start the engine and verify that vacuum is applied to the end of the disconnected ventilation hose while the engine is idling. If vacuum is not applied to the ventilation hose, perform the p ...