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:

Tcs/DSC Indicator Light
Purpose/Function The TCS/DSC indicator light, built into the instrument cluster, informs the driver of the following vehicle conditions. TCS is operating. (Drive wheel is slipping.) DSC is operating. (Vehicle side-slip condition.) Roll over mitigation (RO ...

Relay And Fuse Block Removal/Installation
1. Remove the battery tray.. 2. Remove the air cleaner case.. 3. While pressing the relay and fuse block upper cover tab in the direction of the arrow (1) shown in the figure, lift up the relay and fuse block upper cover in the direction of the arrow (2) to detach the relay and fuse block up ...

Heater Core Inspection
1. Inspect the heater core for damage, cracks, and water leakage. If there is any malfunction, replace the heater core. 2. Visually inspect the fins for bending. If there is any bending, use the end of a flathead screwdriver to straighten the fins. 3. Visually inspect ...