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:

Tire Pressure Monitoring System Set Switch
Purpose The tire pressure monitoring system set switch is used to initialize the tire pressure monitoring system. Construction, Operation The tire pressure monitoring system set switch is installed to the instrument panel. The tire pressure monitoring sy ...

Cooling Fan Relay
Purpose, Function The cooling fan relay operates by receiving the signal from the PCM to supply power to the cooling fan motor. Construction The cooling fan relay is installed on the relay and fuse block. Operation The contact point is on when the battery vo ...

Mass Air Flow (MAF) Sensor/Intake Air Temperature (Iat) Sensor No.1 Removal/Installation
NOTE: Because the IAT sensor No.1 is integrated in the MAF sensor, replacing the IAT sensor No.1 includes replacement of the MAF sensor/IAT sensor No.1. 1. Disconnect the negative battery cable.. 2. Disconnect the MAF sensor/IAT sensor No.1 connector. 3. Remove the MAF sensor/IA ...