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 Sash Molding Removal
WARNING: Using a utility knife with bare hands can cause injury. Always wear gloves when using a utility knife. 1. Remove the rear door garnish. (rear side). 2. Remove the double-sided adhesive tape in the position shown in the figure using the utility knife. CAUTION: ...

Variable Valve Timing Mechanism
Outline Achieves optimum valve timing according to the driving conditions by the variable valve timing mechanism changing the phases of the camshaft. An electric type variable valve timing mechanism on the intake side and a hydraulic pressure type on the exhaust side has been ad ...

Starter Relay [Skyactiv G 2.0]
Purpose, Function The starter relay supplies power to the starter by receiving the signal from the PCM. Construction The starter relay is installed to the relay and fuse block. Operation The contact point is on when the voltage is supplied to the coil based on ...