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:

Electric Power Steering (Eps) Control Module
Purpose/ Function The EPS control module (CM) calculates the optimum assist current based on the steering torque signal from the torque sensor installed to the steering column and the vehicle speed signal sent via CAN transmission from the PCM. The EPS CM controls the following ...

Audio Control Switch Operation
When the audio unit is turned on, operation of the audio unit from the steering wheel is possible. NOTE Because the audio unit will be turned off under the following conditions, the switches will be inoperable. • When the ignition is switched off. • When the power button on the audio uni ...

Fuel Tank Pressure Sensor Inspection
Voltage Inspection NOTE: The fuel tank pressure sensor cannot be removed as a single unit. When replacing the fuel tank pressure sensor, replace it together with the charcoal canister as a single unit. 1. Disconnect the negative battery cable.. 2. Disconnect the fuel tank pres ...