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:

Control Valve Body [Fw6 A EL, Fw6 Ax EL]
Purpose/Function The control valve body controls the hydraulic pressure generated by the oil pump by each solenoid valve. In addition, the oil passages which introduce hydraulic pressure to the pistons for each clutch and brake is formed by the switching of each built-in shift valve. ...

Mechanical
Outline The sliding resistance*1 has been reduced by: the adoption of a rocker arm (built into needle roller bearing) reducing load on the valve spring narrowing down the crankshaft journal optimizing the piston skirt shape adoption of ...

Front Seat Cushion Frame Removal/Installation
WARNING: Handling a side air bag improperly can accidentally operate (deploy) the air bag, which may seriously injure you. Read the service warnings/cautions in the Workshop Manual before handling the front seat (side air bag integrated).. If the sliding mechanisms on both side ...