Bypasses the closed throttle plate with a metered amount of air so the engine can hold a steady idle under varying load. Drive-by-wire engines have no separate valve — the throttle body itself opens fractionally instead. The trap worth knowing is that idle control is usually the system compensating rather than the system failing: an unmetered air leak leaves the valve commanded fully shut and still unable to bring idle speed down, which sets an idle control code on a perfectly good valve. Read the commanded position before replacing anything.
Also known as: iac, iac valve, idle valve, idle speed control valve, isc valve, stepper motor, idle control motor
Referenced by 9 codes
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At idle the throttle plate is shut. The engine still needs air, and it needs varying amounts of it — more when cold, more when the air conditioning compressor engages, more when th...
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