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:

Power Metal Oxide Semiconductor Field Effect Transistor (Power Mos Fet) Removal/Installation [Full Auto Air Conditioner]
NOTE: When removing the power MOS FET, perform the procedure in the posture shown in the figure. 1. Disconnect the negative battery cable.. 2. Remove the dashboard under cover.. 3. Disconnect the connector. 4. Rotate the power MOS FET (2) while pressing the tab (1). ...

Exhaust Manifold
Purpose, Function By lengthening the exhaust passage, the transmission of exhaust pressure waves to other cylinders can be delayed, and the amount of gas exhausted from a cylinder and forced back inside the combustion chamber is reduced By reducing the residual gas, the temperature i ...

Rear Fender Panel Removal [Panel Replacement]
Symbol Mark Removal Procedure CAUTION: Avoid cutting with a blowtorch or similar tools as the insulator (shaded area) is flammable. 1. Rough cut the 3 locations indicated by (A) shown in the figure. 2. Drill the 90 locations indicated by (B) shown in the figure. ...