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:

Magnetic Clutch Adjustment [Manual Air Conditioner]
1. Measure the clearance around the entire circumference between the pressure plate and A/C compressor pulley using a thickness gauge. 2. Verify the clearance. If not within the specification, remove the pressure plate and adjust the clearance by changing the shim (0.2 mm {0.008 i ...

C Pillar Trim Removal/Installation
1. Disconnect the negative battery cable.. 2. Remove the following parts: a. Trunk board. b. Trunk end trim. c. Rear scuff plate. d. Trunk side trim. e. D-pillar trim. 3. Partially peel back the seaming welt. 4. Remove the fastener A. 5. Take the shaded area shown in the figure ...

Discharge Headlight System
Outline The discharge headlight system utilizes a gas discharge type light to emit a white light resembling sunlight over a wide area. Also, use of the gas discharge type light realizes high efficiency, low power consumption lighting. Structural View System Wiring Diagram ...