P0506

Idle Control System RPM - Lower Than Expected

Idle / air control Generic OBD-II High

What it means

P0506 means the engine is idling slower than the ECM's target speed. The most common cause is a carbon-fouled throttle body or a sticking idle air control valve restricting the air the engine needs at idle. A low idle can make the engine feel rough and, at worst, stall when you come to a stop — so it is worth fixing promptly.

High

Can I keep driving? Drivable but frustrating and risky — the engine may stall at stops or idle, so fix it promptly to avoid being stranded.

Real-world scan data

Seen in

641

scans in the past year

Found in

0.1%

of scans

0.2%

of scans that found faults

Appears alongside · share of P0506 scans

P0507in 78.3% of scans

P22A3in 73.2% of scans

P2205in 72.7% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Idle speed lower than normal
Engine stalls, especially when stopping or coasting to a stop
Rough or unstable idle
Check-engine light on

Common causes

Most likely first

Carbon-fouled or dirty throttle body restricting idle airflowLikely
Faulty or sticking idle air control (IAC) valveCommon
Vacuum or intake restriction affecting idle airCommon
Dirty or faulty mass airflow sensor giving a wrong readingLess often
Wiring fault in the idle control circuitLess often

How to diagnose & fix

Work through it in order

Clean the throttle body and idle air passages — the most common fix.
Inspect, clean, or replace the idle air control valve if fitted.
Check for intake restrictions and confirm the throttle plate closes/opens correctly.
Inspect the MAF sensor and idle-circuit wiring, then relearn idle, clear, and re-test.

FAQ

Quick answers

Is it safe to drive with P0506?+

It is drivable, but a low idle can cause stalling at stops, which is unsafe in traffic. Fix it promptly.

Can I just clear P0506?+

You can, and some cars need an idle relearn after cleaning, but the code returns if the throttle body, IAC, or airflow problem is not corrected.

Read & clear P0506 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX