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:

Windshield Wiper Motor Inspection
1. Disconnect the negative battery cable.. 2. Remove the following parts: a. Windshield wiper arm and blade. b. Cowl grille. Windshield Wiper Motor Inspection 1. Apply battery positive voltage and connect the ground to the windshield wiper motor terminals as indicated in the table below a ...

Oil Filter
Purpose, Function Engine oil is filtered by passing engine oil through the oil filter element. Construction The oil filter is installed on the right side surface of the cylinder block. A spin-on type (full-flow type) oil filter has been adopted. The bypa ...

Speedometer
Purpose The speedometer notifies the driver of the speed at which the vehicle is traveling. Function The instrument cluster controls the speedometer needle based on the vehicle speed signal from the PCM and displays the current vehicle speed. Construction An an ...