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:

Shift Point Control (Manual Shift Control) [Fw6 A EL, Fw6 Ax EL]
Outline The TCM operates the manual shift control when the M position is selected. If the M position is selected, manual shifting is prioritized according to the driver’s shift up/shift down operation. However, to assure driving safety and protect the ATX, minimum automatic sh ...

Front Side Frame Removal [Panel Replacement]
Symbol Mark Removal Procedure 1. Drill the 15 locations indicated by (A) shown in the figure. 2. Drill the 4 locations indicated by (B) shown in the figure. NOTE: When drilling the 4 locations indicated by (B) shown in the figure, do not drill a hole all the way through or there ...

Seat Precaution
WARNING Make sure the adjustable components of a seat are locked in place: Adjustable seats and seatbacks that are not securely locked are dangerous. In a sudden stop or collision, the seat or seatback could move, causing injury. Make sure the adjustable components of the seat are locked in pl ...