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:

Front Side Frame Removal [Panel Replacement]
Symbol Mark Removal Procedure 1. Drill the 15 locations indicated by (A) shown in the figure. 2. Drill the 4 locations indicated by (B) shown in the figure. NOTE: When drilling the 4 locations indicated by (B) shown in the figure, do not drill a hole all the way through or there ...

Non Return Valve
Purpose, Function Assures safety by preventing fuel from returning to the fuel filler opening. Construction The non-return valve cannot be removed as it is installed inside the fuel tank. 2WD AWD A single valve type has been adopted for the non-return v ...

Rear Shock Absorber Removal/Installation
1. Remove in the order indicated in the table. 2. Install in the reverse order of removal. 1 Rear shock absorber upper nut (See Rear Shock Absorber Upper nut Installation Note.) 2 Rear shock absorber lower bolt 3 ...