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:

Low Fuel Warning Light
Purpose The low fuel warning light warns the driver that the remaining fuel level is low. Function The instrument cluster calculates the fuel quantity based on the following CAN signals, and if a remaining fuel amount of approx. 10 L {2.6 US gal, 2.2 Imp gal} (fuel gauge ...

Oil Cooler Removal/Installation [Fw6 A EL, Fw6 Ax EL]
1. Disconnect the negative battery cable.. 2. Remove the front under cover No.2.. 3. Drain the ATF.. 4. Drain the engine coolant.. 5. Remove in the order indicated in the table. 1 Water hose (connected to the water pipe) 2 Water hose ...

Coupler Component Removal/Installation [Fw6 A EL, Fw6 Ax EL]
WARNING: A hot transaxle and ATF can cause severe burns. Turn off the engine and wait until they are cool. Always wear protective eye wear when using the air compressor. If the air compressor is used, any particles of dirt or soiling could spatter and get into the eyes. ...