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:

Rear Door Checker Removal/Installation
1. Fully close the rear door glass. 2. Disconnect the negative battery cable.. 3. Remove the rear door trim.. 4. Remove the rear door speaker.. 5. Remove bolt. 6. Remove nuts. 7. Pull out the rear door checker from the rear speaker installation hole. 8. Install in the reverse ...

Air Bag System Warning Light [Two Step Deployment Control System]
Purpose The air bag system warning light notifies the driver of a malfunction in the SRS air bag system. Function If a malfunction occurs in the SRS air bag system, the air bag system warning light illuminates or flashes. Construction LEDs (light-emitting d ...

Shift Position Indicator Light [Fw6 A EL, Fw6 Ax EL]
Purpose/Function The shift position indicator light indicates the selector lever position. Construction The shift position indicator light is built into the instrument cluster. Operation The TCM sends a shift position indicator light illumination request signal ...