Mazda CX-5 Service & Repair Manual: Heated Oxygen Sensor (HO2 S) Heater Control

Mazda CX-5 Service & Repair Manual / Engine / Control / Heated Oxygen Sensor (HO2 S) Heater Control

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

Engine Coolant Temperature (ECT) Sensor

Purpose/Function Detects the ECT as basic information for mainly determining the fuel injection amount. Detects the ECT and inputs it to the PCM as an ECT signal. The ECT sen ...

Heated Oxygen Sensor (HO2 S) Inspection

HO2S Inspection 1. Connect the M-MDS to the DLC?2. 2. Switch the ignition ON (engine on). 3. Warm up the engine to normal operating temperature. 4. Access the following PIDs using the M-MDS.. ...

Other materials:

Air Mix Actuator Removal/Installation [Full Auto Air Conditioner]
Driver-side 1. Disconnect the negative battery cable.. 2. Remove the following parts: a. Side wall (driver-side). b. Front heat duct (LH). 3. Disconnect the air mix actuator connector. 4. Remove the screw. 5. Remove the driver-side air mix actuator. 6. Install in the reverse order ...

Main Relay Control [Skyactiv G 2.0]
Outline Supplies power to each part by switching the main relay on/off at the optimal timing according to the vehicle conditions. Block Diagram Operation When the ignition is switched ON, the main relay turns on and electrical power is supplied to each sensor and devic ...

Compression Inspection
WARNING: Hot engines and oil can cause severe burns. Be careful not to burn yourself during removal/installation of each component. Fuel vapor is hazardous. It can very easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel. Fuel ...