Mazda 6 Facelift 2005, Training Manual

Page: 34 / 274

Petrol Engines Engine
Throttle Valve Actuator
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By controlling the throttle actuator, the PCM sets an optimal throttle valve opening angle
according to the engine conditions.
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The PCM calculates a target throttle valve opening angle based on the accelerator pedal
depression amount.
•
The PCM calculates the target throttle valve opening angle based on signals from APP
sensors No.1 and No.2. In order to change the actual throttle valve opening angle to the
calculated target opening angle, the PCM controls the direction and size of the current
sent to the throttle actuator. TP sensors No.1 and No.2 detect the actual throttle valve
opening angle.
•
The PCM sends electrical current to the throttle actuator to achieve the target opening
angle.
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The engine idling speed can be controlled through PCM control of the throttle valve. Due
to this, the previous IAC valve has been eliminated.
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After the ignition switch is turned off, the PCM opens and closes the throttle valve. At this
time, the input voltage of the TP sensor at the fully closed position and the fully open
position is stored. This learned voltage measurement at the fully closed and open
position is used when correcting the throttle opening angle.
•
If the PCM detects any of the following malfunctions, it limits the throttle valve opening
angle, performs fuel cut and other control measures to limit engine output, as well as
stopping the flow of electricity to the throttle actuator. When this flow of electricity is
stopped, the throttle valve is limited to the minimum opening angle possible for driving:
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TP sensor No.1 malfunction
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TP sensor No.2 malfunction
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APP sensor No.1 malfunction
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APP sensor No.2 malfunction
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Throttle actuator malfunction
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PCM internal circuit (for electronic throttle control) malfunction
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Throttle body (throttle valve and return spring) malfunction
01-20 Service Training Mazda6 Facelift