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:

Catch Tank
Purpose, Function Suppresses pulsation occurring before evaporative gas is inducted into the intake manifold. Construction The catch tank is installed in the engine compartment. Operation When evaporative gas flows from the charcoal canister to the purge sol ...

Starting the Engine
WARNING Radio waves from the key may affect medical devices such as pacemakers: Before using the key near people who use medical devices, ask the medical device manufacturer or your physician if radio waves from the key will affect the device. NOTE • The key must be carried because the ke ...

Clutch Release Collar Inspection [C66 M R]
CAUTION: Do not clean the clutch release collar with cleaning fluids or a steam cleaner because it is filled with grease. Operation Inspection 1. Turn the collar while applying force in the axial direction, and inspect for sticking, excessive resistance, and an abnormal noise. ...