P0506 — Idle Air Control System RPM Lower Than Expected
Drive with caution — fix soon.
What P0506 means
P0506 means the engine's idle speed is lower than the computer expects. This is usually caused by something restricting airflow at idle, like a dirty throttle body, a vacuum leak, or a faulty idle air control valve. It can make the engine feel like it wants to stall when stopped.
Common symptoms
- Check engine light is on
- Low or rough idle
- Engine stalling at stops
- Engine shaking or vibration at idle
- Hesitation when coming to a stop
Common causes
- Dirty or carboned-up throttle body
- Faulty idle air control valve
- Vacuum leak in intake hoses
- Clogged or dirty air intake passages
- Excessive electrical or AC load at idle
Typical repair cost
$100 – $450
Varies by vehicle and root cause.
Frequently asked questions
Can I drive with a P0506 code?
Usually yes, but the engine may stall at stops, which can be inconvenient or unsafe in traffic. Get it checked before it worsens.
How much does fixing P0506 cost?
Often $100 to $450. A throttle body cleaning is cheap, while replacing an idle air control valve costs a bit more.
Is P0506 a serious problem?
It's moderate. The biggest concern is stalling at idle, but it doesn't usually cause lasting engine damage if fixed reasonably soon.
Could a dirty throttle body cause P0506?
Yes, very commonly. Carbon buildup restricts the small amount of air the engine needs at idle, dropping the RPM below target.