Mazda CX-5 Service & Repair Manual: Air Fuel Ratio (A/F) Sensor Heater Control
Outline
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Based on the control of the A/F sensor 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.
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Both emission performance and sensor protection have been improved by duty control of the heater according to engine operation conditions (exhaust gas temperature).
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A pre-heater has been adopted to prevent water, produced from the exhaust system when the engine is started, from adhering to the sensor and damaging it.
Block Diagram
Operation
Pre-heater control
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The A/F sensor heater is operated at a duty ratio of approx. 15% within the specified time directly after the engine is started.
Normal control
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The PCM operates the A/F sensor based on the following control conditions:
|
Output duty ratio |
Control condition |
|
0% |
|
|
0?100% (Duty ratio determined by measuring the element temperature by the A/F sensor heater element impedance) |
|
Accelerator Pedal Position (App) Sensor
Purpose/Function
Detects the accelerator pedal depression amount as basic information for
mainly determining the throttle valve opening.
Detects the accelerator pedal depression amou ...
Air Fuel Ratio (A/F) Sensor Inspection
A/F Sensor 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-M ...
Other materials:
Power Metal Oxide Semiconductor Field Effect Transistor (Power Mos Fet) [Full
Auto Air Conditioner]
Purpose
The power MOS FET controls the blower motor rotation speed.
Function
The power MOS FET controls the supply voltage to the blower motor based on
the gate voltage sent from the climate control unit, and adjusts the fan rotation
speed (airflow volume).
Constructi ...
B Pillar Lower Trim Removal/Installation
1. Remove the front scuff plate..
2. Remove the rear scuff plate..
3. Partially peel back the seaming welt.
4. Take the shaded area shown in the figure, and pull the B-pillar lower trim
in the direction of the arrow in the order of (1), (2) while detaching hooks A,
pins B.
5. Take th ...
Front Fog Light Bulb Removal/Installation
1. Disconnect the negative battery cable..
2. Remove the mudguard screws.
3. Disconnect the connector.
4. Rotate the front fog light bulb in the direction of the arrow (1) shown in
the figure and remove it from the front fog light in the direction of the arrow
(2) shown in the figu ...
