B4000 SE Cab Plus 4 4WD V6-4.0L OHV (2000)
Idle Speed/Throttle Actuator - Electronic: Description and Operation
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Controls engine idle speed and provides a dashpot function.
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Meters intake air around the throttle plate through a bypass within the IAC valve assembly and throttle body.
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The PCM determines the desired idle speed or bypass air and signals the IAC valve assembly through a specified duty cycle. The IAC valve
responds by positioning the IAC valve to control the amount of bypassed air. The PCM monitors engine rpm and increases or decreases the IAC
duty cycle in order to achieve the desired rpm.
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The PCM uses the IAC valve assembly to control the following:
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No touch start.
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Cold engine fast idle for rapid warm-up.
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Idle (corrects for engine load).
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Stumble or stalling on deceleration (provides a dash pot function).
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Over-temperature idle boost.
