Mazda CX-5 Service & Repair Manual: Heated Oxygen Sensor (HO2 S) Heater Control [Skyactiv G 2.0]

Mazda CX-5 Service & Repair Manual / HVAC / General / Heated Oxygen Sensor (HO2 S) Heater Control [Skyactiv G 2.0]

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

Front Heat Duct Removal/Installation

1. Disconnect the negative battery cable.. 2. Remove the following parts: a. Dashboard under cover. b. Side wall. c. Glove compartment. 3. Detach the tab and remove the front heat duct. LH ...

Heater Core

Purpose The heater core heats passing air. Function A portion of the engine coolant is taken into the heater core to heat the air passing through the heater core. Co ...

Other materials:

Tweeter Inspection
1. Disconnect the negative battery cable.. 2. Remove the side speaker grille.. 3. Remove the tweeter.. 4. Verify that the resistance between the tweeter terminals is as indicated in the table. If not as indicated in the table, replace the tweeter. Without Bose® With B ...

Precaution
Intermittent Concern Troubleshooting Vibration method If a malfunction occurs or becomes worse while driving on a rough road or when the engine is vibrating, perform the following steps. NOTE: There are several reasons why vehicle or engine vibration could cause an electr ...

Air Bag System Warning Light [Two Step Deployment Control System]
Purpose The air bag system warning light notifies the driver of a malfunction in the SRS air bag system. Function If a malfunction occurs in the SRS air bag system, the air bag system warning light illuminates or flashes. Construction LEDs (light-emitting d ...