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 Seat
Split Folding The seatbacks can be folded down to provide more space in the luggage compartment. WARNING Tightly secure cargo in the luggage compartment when it is transported with the seatbacks folded down: Driving without tightly securing cargo and luggage is dangerous as it could move and ...

Timing Chain, Chain Tensioner
Purpose, Function Timing chain The timing chain transmits the rotation force of the crankshaft to the camshaft to perform the rotation timing of the crankshaft and camshaft. Chain tensioner The chain tensioner constantly maintains the timing chain tension and the timing ch ...

Shift Control Module Removal/Installation [C66 M R]
Removal 1. Shift the shift lever to the neutral position. 2. Remove the plug hole plate.. 3. Disconnect the negative battery cable.. 4. Remove the air cleaner and air hose as a single unit.. 5. Remove the battery and battery tray.. 6. Disconnect the control cable from the transaxle. a. ...