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:

Starter Interlock Switch [Skyactiv G 2.0]
Purpose, Function The starter interlock switch mechanism prevents vehicle surge when the engine is started, enhancing safety. The engine cannot be started unless the clutch is depressed. Construction The mechanism is provided with a starter interlock switch on the circuit ...

Low And Reverse Brake [Fw6 A EL, Fw6 Ax EL]
Purpose/Function The low and reverse brake stops the rotation of the front internal gear and rear planetary carrier while in 1GR and in reverse, locking them to the transaxle case. Construction The low and reverse brake consist of the following parts shown in the figure. ...

A/C Unit
Outline The A/C unit which integrates the cooling and heater units has been adopted. Construction The A/C unit consists of the following parts. Operation Air Mix Door Operation The air mix door, installed in the A/C unit, controls HOT or COLD position, depend ...