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:

Refrigerant Pressure Sensor Removal/Installation [Full Auto Air Conditioner]
1. Disconnect the negative battery cable.. 2. Discharge the refrigerant.. 3. Disconnect the refrigerant pressure sensor connector. CAUTION: If moisture or foreign material enters the refrigeration cycle, cooling ability will be lowered and abnormal noise will occur. Always immediate ...

Windshield Wiper Motor Inspection
1. Disconnect the negative battery cable.. 2. Remove the following parts: a. Windshield wiper arm and blade. b. Cowl grille. Windshield Wiper Motor Inspection 1. Apply battery positive voltage and connect the ground to the windshield wiper motor terminals as indicated in the table below a ...

DRL (Daytime Running Light) System
Outline The DRL system automatically switches the headlights to HI beams (50% dim) or illuminates the DRL bulb when the ignition is switched ON (engine on), the parking brake is released, and the shift lever is in a position other than P (ATX). The front body control module ( ...