Idle Speed Control

Idle Air Control (IAC) valve controls engine idle speed by regulating flow of air to engine when throttle plates and CTP switch are closed. IAC valve is mounted on throttle valve housing.

IAC valve is operated by a cycled DC (duty cycle) voltage. PCM supplies cycled voltage to IAC switch to regulate engine idle speed with a warm engine between 650 and 750 RPM. The duty cycle will vary depending on engine load and engine conditions. Since the idle system is adaptive, no adjustments are necessary.