P0507 SATURN - Idle Speed High
- Electric throttle control actuator misadjusted or damaged
- Faulty Electric throttle control actuator
- Intake air leak
- Poor electrical connection to the Intake Air Control (IAC) valve
- Engine hard to start
- Rough or erratic idle speed
The Idle Air Control (IAC) valve is a Powertrain Control Module (PCM) controlled stepper motor located on the throttle body. The stepper motor drives a valve pintle which protrudes into a passage that bypasses the throttle plates. The PCM commands the IAC valve pintle to extend to decrease the idle speed. The bypass air flow is reduced and the idle speed decreases as the pintle approaches its seat. The PCM retracts the IAC valve pintle away from its seat to increase the idle speed. The retracting of the IAC valve pintle allows more air to bypass the throttle plates. One of the PCMs uses for the IAC system is to maintain a desired idle speed. This DTC sets when the PCM detects an engine speed outside of the IAC's range of control.