An IAC valve allows air to bypass the throttle plate.

An IAC valve allows air to bypass the throttle plate.

• A. True
• B. False
• C. It regulates fuel pressure
• D. It measures air temperature

Answer: (A)

An idle air control valve is designed to bypass the throttle plate and regulate how much air enters the engine at idle. When the throttle is closed at idle, the engine still needs air, so the IAC opens a small bypass passage to admit a controlled amount of air. The engine control unit then adjusts this air flow to keep the idle RPM steady under different conditions, such as changes in engine temperature, electrical load, or A/C usage. It isn’t involved in regulating fuel pressure or measuring air temperature, which are functions of other components. So the statement is true.

An idle air control valve is designed to bypass the throttle plate and regulate how much air enters the engine at idle. When the throttle is closed at idle, the engine still needs air, so the IAC opens a small bypass passage to admit a controlled amount of air. The engine control unit then adjusts this air flow to keep the idle RPM steady under different conditions, such as changes in engine temperature, electrical load, or A/C usage. It isn’t involved in regulating fuel pressure or measuring air temperature, which are functions of other components. So the statement is true.