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:
Low Engine Coolant Temperature Indicator Light (Blue)/High Engine Coolant Temperature
Warning Light (Red)
Purpose
Low engine coolant temperature indicator light (blue)
The low engine coolant temperature indicator light (blue) notifies the driver
that the engine coolant temperature is low and vaporization of the fuel is difficult.
High engine coolant temperature warning light (red)
...
Check Valve
Except U.S.A. And CANADA
Purpose, function
The check valve maintain the pressure in the fuel tank at constant pressure.
Construction
The check valve is installed to the side of the charcoal canister.
Mainly consists of valve, umbrella, and spring.
O ...
Reporting Safety Defects (U.S.A.)
If you believe that your vehicle has a defect which could cause a crash or could
cause injury or death, you should immediately inform the National Highway Traffic
Safety Administration (NHTSA) in addition to notifying Mazda Motor Corporation (Your
Mazda Importer/Distributor).
If NHTSA receive ...
