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:

Oil Pump [Fw6 A EL, Fw6 Ax EL]
Purpose/Function The oil pump generates hydraulic pressure in the oil line of the automatic transaxle together with supplying lubrication to powertrain related parts. Construction The oil pump has adopted a gear type with built-in outer and inner rotors. The inner roto ...

Front Frame (Rear) Removal [Panel Replacement]
Symbol Mark Removal Procedure 1. Drill the 33 locations shown in the figure. NOTE: When drilling, do not drill a hole all the way through or there could be a problem when installing the new part. 2. Remove the front frame (rear). ...

Rear Body Control Module (Rbcm) Configuration (Using As Built Data)
NOTE: If the configuration is performed using As-Built data, the set value of the personalization function is reset to the initial value (condition when shipped from factory). Verify the set value with the customer and perform the personalization function setting after performing th ...