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:

Drive Belt Inspection [Skyactiv G 2.0]
Generator Drive Belt NOTE: The generator drive belt deflection/tension inspection is not necessary with the adoption of the drive belt auto tensioner. 1. Verify that the indicator part of the cast hexagon on the drive belt auto tensioner is within the normal range. If ...

Clock Spring Adjustment [Two Step Deployment Control System]
1. Set the front wheels straight ahead. CAUTION: The clock spring will break if over?wound. Do not forcibly turn the clock spring. 2. Turn the clock spring clockwise until it stops. 3. Turn the clock spring counterclockwise approx. 2 turns. 4. Align the mark on the clo ...

Gear Position Indicator [Fw6 A EL, Fw6 Ax EL]
Purpose/Function The gear position indicator illuminates while under manual shift control and displays the gear number while driving. Construction The gear position indicator is built into the instrument cluster. Operation The TCM sends a gear position indic ...