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:

Assist Handle Removal/Installation
Removal 1. Insert a tape-wrapped flathead screwdriver into the service hole and remove the assist handle covers. 2. Remove the assist handle in the direction of the arrow (1) and (2), while detach clips. NOTE: Remove the assist handle by shaking it up and down. Install ...

TCM Configuration [Fw6 A EL, Fw6 Ax EL]
NOTE: The TCM is built into the control valve body. 1. Verify TCM configuration implementation necessity for replacement parts. Replacement part Configuration necessity Control valve body replacement Necessary ...

Cruise Main Indicator Light (Amber)
Purpose/Function Illuminates while the cruise control system is in standby mode to inform the driver that the cruise control system is on standby. Construction Built into the instrument cluster. Operation Illuminates while the cruise control system is on sta ...