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:

Fuel Filler Cap Inspection
Leakage Inspection 1. Perform the following tester (evaporative emission system tester (134-01049A)) self-test: NOTE: If the tester does not work correctly during self-test, refer to the tester operators manual for more detailed procedures. a. Verify that the gas cylinder valve ...

Drive Belt
Purpose, Function The drive belt transmits rotation force of the crankshaft pulley to the pulley for the auxiliary parts. Construction The drive belt is installed to the front of the engine. A V-ribbed belt has been adopted for the drive belt. The wat ...

Oil Pressure Switch Inspection
1. Switch the ignition ON (engine off) and verify that the oil pressure warning light is illuminated. 2. Start the engine and verify that the oil pressure warning light turns off. If the oil pressure warning light is not illuminated or remains illuminated, inspect the wiring harness ...