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:

Rear Door Trim Removal/Installation
1. Insert a tape-wrapped flathead screwdriver in the position indicated by the arrow (1) in the figure and remove the inner handle cover while detach tabs A, pin B. 2. Remove the screw C. 3. Remove the cover D, then remove the screw E. 4. Take the shaded area shown in the figur ...

Turbine/Input Shaft Speed Sensor, Output Shaft Speed Sensor [Fw6 A EL, Fw6 Ax EL]
Purpose/Function The turbine/input shaft speed sensor detects the rotation speed of the input shaft (low clutch drum). The output shaft speed sensor detects the rotation speed of the output shaft (primary gear). The turbine/input shaft speed sensor and output shaft speed ...

Washer Tank Removal/Installation
With Washer Fluid-level Sensor 1. Disconnect the negative battery cable.. 2. Set the front over fender aside.. 3. Set the mudguard (RH) aside.. 4. Remove the front bumper.. 5. Remove the bracket. 6. Disconnect the washer motor connector. 7. Disconnect the washer fluid-level sensor c ...