Code P0507 on the 2024 Kia Forte indicates the engine idle speed is higher than the ECM expects. Modern vehicles control idle electronically through the throttle body - when idle speed exceeds programmed parameters despite the ECM's attempts to lower it, P0507 sets.
Idle Speed Control
The Forte uses electronic throttle control without a traditional idle air control valve. The ECM precisely controls the throttle plate position to maintain target idle speed. When the engine idles too fast despite commanding the throttle closed, the ECM determines something is allowing extra air into the engine.
High Idle Symptoms
With P0507, you'll notice the engine idles faster than normal - typically 200+ RPM above specification. The engine may 'hang' at higher RPM when releasing the accelerator before settling to idle. Fuel economy decreases with constantly elevated idle.
Common Causes
Vacuum leaks are the most common cause - air entering after the throttle body increases idle speed. A dirty or sticking throttle body prevents proper closure. Intake manifold gasket leaks, PCV system issues, or EVAP purge valve stuck open allow unmeasured air entry.
Diagnostic Focus
Listen and look for vacuum leaks. Check throttle body cleanliness and operation. Monitor purge valve and PCV valve operation. Inspect intake gaskets and hoses for air leaks that would elevate idle.