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 Variable Valve Timing Actuator, Hydraulic Variable Valve Timing Actuator Removal/Installation
WARNING: A hot engine can cause severe burns. Turn off the engine and wait until it is cool before servicing. CAUTION: Do not disassemble the electric variable valve timing actuator and hydraulic variable valve timing actuator because they are precision units. If ...

Power Window Main Switch Inspection
1. Disconnect the negative battery cable.. 2. Remove the following parts: a. Inner garnish. (driver's side). b. Front door trim. (driver's side). c. Power window main switch. 3. Connect the power window main switch connector. 4. Connect the negative battery cable.. 5. Measure t ...

Crankshaft Position (CKP) Sensor Inspection
Visual Inspection CAUTION: When foreign material such as an iron chip is on the CKP sensor, it can cause abnormal output from the sensor because of flux turbulence and adversely affect the engine control. Be sure there is no foreign material on the CKP sensor when replacing. ...