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:

Front ABS Wheel Speed Sensor Removal/Installation
1. Remove the mudguard.. 2. Remove in the order indicated in the table. 3. Install in the reverse order of removal. 4. After installation, verify that there is no twisting in the front ABS wheel-speed sensor. 1 Connector 2 Bolt ...

Engine Coolant Temperature (ECT) Sensor Inspection
Resistance Inspection WARNING: When the engine is hot, it can badly burn. Turn off the engine and wait until it is cool before removing the ECT sensor. ECT Sensor No.1 1. Remove the ECT sensor No.1.. 2. Place the ECT sensor No.1 in water with a thermometer, and heat the water ...

Fuel Pump Control Module Inspection
1. Perform the KOEO self-test.. 2. Verify that a fuel pump control module related DTC is detected.. If DTCs are detected, repair the malfunctioning part according to the applicable DTC troubleshooting.. If a DTC is not detected, go to the next step. 3. Inspect the followin ...