P0507 Code: Idle Air Control System RPM Higher Than Expected

💨What Does P0507 Mean?

Your engine has a target idle speed — usually somewhere around 600–800 RPM once warm. The powertrain control module (PCM) holds idle at that target by precisely controlling how much air bypasses the throttle, using either an idle air control (IAC) valve on older vehicles or the electronic throttle body on newer drive-by-wire systems.

P0507 sets when the actual idle RPM stays higher than the PCM’s commanded target by more than a set threshold (often around 100–200 RPM above target), and the system can’t bring it back down. In plain terms: the engine is getting more air at idle than the computer is asking for, and the idle control has run out of room to compensate.

🔎Symptoms of P0507

• High idle speed — the defining symptom (idling well above normal, sometimes 1,000–1,500 RPM)
• Check Engine Light
• Idle doesn’t drop to normal even after the engine is fully warm
• Faster-than-normal creep at stops on automatics; brakes feel like they’re working against the engine
• A hissing sound near the intake if a vacuum leak is the cause

🔧Common Causes of P0507

1) Vacuum leak (the #1 cause)

Unmetered air entering after the throttle plate raises idle speed and the PCM can’t close the idle air path enough to compensate. Cracked vacuum hoses, leaking intake manifold gaskets, a faulty PCV system, or a leaking brake booster hose are the usual culprits. A vacuum leak often sets lean codes like P0171 alongside P0507.

2) Dirty or carboned throttle body

Carbon buildup on the throttle plate and bore disrupts the precise airflow control the PCM relies on, leaving idle too high.

3) Sticking or faulty IAC valve (older vehicles)

On vehicles with a separate idle air control valve, a stuck or failing IAC can hold the idle air passage open too far.

4) Throttle relearn needed / PCV fault

On drive-by-wire vehicles, the throttle body sometimes needs an idle relearn after cleaning or a battery disconnect. A PCV valve stuck open also adds unmetered air and raises idle.

🚦How Serious Is P0507?

P0507 is generally low to moderate severity. The car remains drivable, but a high idle wastes fuel, can make the vehicle creep harder at stops (which puts extra load on the brakes), and points to an underlying air-control problem worth fixing. If the high idle is significant, take care in stop-and-go traffic and when parking.

🩺How to Diagnose P0507

1. Confirm the actual idle RPM against the specification for your vehicle, and note any companion codes (P0505/P0506 or lean codes) that narrow the cause.
2. Check for vacuum leaks first — listen for a hiss at idle and spray a little carb cleaner around intake boots, vacuum hoses, the PCV, and the brake booster line. A change in idle RPM when you spray a spot pinpoints the leak. A smoke test is the most thorough method.
3. Inspect the throttle body for carbon buildup on the plate and bore.
4. Check the PCV valve and hose — a stuck-open PCV adds unmetered air.
5. Test the IAC valve (older systems) for sticking, or confirm whether the electronic throttle needs an idle relearn after recent cleaning or battery work.
6. Repair, relearn, and recheck. Fix the leak or clean the throttle body, perform an idle relearn if applicable, clear the code, and verify idle returns to target.

🛠️How to Fix P0507

💰P0507 Repair Cost Estimates

Costs vary by make and model and by how accessible the throttle body and intake components are. The cheapest fixes — sealing a vacuum leak or cleaning the throttle body — resolve most P0507 cases.

❓P0507 FAQs