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:

Disc Pad (Front) Replacement
1. Remove in the order indicated in the table. 2. Install in the reverse order of removal. 3. After installation, depress the brake pedal a few times, rotate the wheel by hand, and verify that the brake does not drag. 1 Bolt 2 Caliper ...

Purge Control
Outline An appropriate amount of evaporative gas is fed into the intake manifold by the purge solenoid valve operation according to the engine operation conditions. This ensures driveability and prevents release of evaporative gas into the atmosphere. The PCM drives the purge so ...

Instrument Cluster Configuration (Using Read/Write Function)
NOTE: When performing configuration, it is necessary to read the vehicle specification information from the instrument cluster before replacing it. Connect the M-MDS to the vehicle and perform vehicle identification before removing the instrument cluster. The vehicle specification i ...