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:

Purge Solenoid Valve Removal/Installation
1. Disconnect the negative battery cable.. 2. Remove the plug hole plate.. 3. Remove the air cleaner and air hose as a single unit.. 4. Disconnect the high pressure fuel pump connector. 5. Disconnect the harness clip as shown in the figure. 6. Remove in the order indicated in the table ...

Liftgate Opener System
Outline A liftgate opener system has been adopted in which the liftgate can be opened just by pressing the liftgate opener switch. The rear body control module (RBCM) performs liftgate opener system fail-safe.. Function When the liftgate opener switch is pressed, the l ...

Power Window Main Switch
Purpose Remote control of door glass open/close and power outer mirror adjustment are possible with occupant seated in the cabin. Function Power window main switch Manual When the power window main switch is operated for manual open/close operation, it sends ...