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:

Starter [Skyactiv G 2.0]
Purpose, Function The starter rotates the crankshaft via the ring gear and it serves as a trigger to start the engine. Construction The starter is installed to the rear part of the engine on the left side. The starter is a coaxial reduction type which can obt ...

Starter Inspection [Skyactiv G 2.0]
On-vehicle Inspection 1. Verify that the battery is fully charged. 2. The starter is normal if it rotates smoothly and without any noise when the engine is cranked. If the starter does not operate, inspect the following: Remove the starter, and inspect the starter unit. ...

Hood Latch Switch Inspection
1. Disconnect the negative battery cable.. 2. Remove the front bumper.. 3. Disconnect the hood latch switch connector.. 4. Verify that the continuity is as indicated in the table. NOTE: Inspect the continuity when the hood is open and closed. If the operation as i ...