What does P0506 mean?
The engine computer detected idle speed lower than expected in the idle control system.
Quick Decision Guide
- Dirty throttle body
- Vacuum or intake leak
- Idle air control valve fault
When to stop driving
If the vehicle stalls when stopping, surges unexpectedly, or idle speed is dangerously high, avoid driving until diagnosed.
Reviewed by ratchit Automotive Solutions for clarity and inspection-first safety framing. Not a substitute for professional diagnosis.
Repair Decision & Cost Guide
Use this guide to decide what to inspect first, what it may cost, and when to move from DIY checks to professional diagnosis.
P0506 is a clue, not a confirmed diagnosis. Inspect simple causes before replacing parts.
DIY vs. Shop
Can you keep driving?
Best first DIY check
Don't replace this first
When to seek a shop
Recommended next action
Estimated Repair Cost
Inspection cost
$0–$25 DIY scanner
Shop diagnostic cost
$80–$150 (typical shop diagnostic fee)
Shop repair cost
$80–$700
Diagnostic uncertainty: This code points to a system or condition, not a guaranteed failed part. Inspect before replacing.
Cost variation: Costs vary by vehicle, location, part quality, labor rate, and the confirmed root cause.
Inspect Before Replacing
These checks are cheap, fast, and rule out the most common causes before spending money on parts.
- 1Inspect intake hoses, PCV hoses, and vacuum lines for cracks or disconnected fittings.
- 2Check for carbon buildup around the throttle plate or idle air passage.
Save this issue to My Garage
Save this issue to My Garage, track what you inspect, and build service history for this vehicle.
V-IQ readiness preview: Medium impact — resolving and tracking this issue may improve your V-IQ readiness. Tracking active codes and resolutions builds a service history we use to estimate V-IQ readiness over time.
Understanding P0506 in detail
P0506 means the ECM is seeing idle speed or idle air control behavior outside the expected range. Modern vehicles control idle with an electronic throttle body, idle air control valve, and learned airflow corrections. Common causes include carbon buildup in the throttle body, vacuum leaks, a dirty or sticking idle air control valve, throttle relearn issues after battery disconnect, intake leaks, or wiring faults. Start with air leaks and throttle/idle cleaning before replacing expensive parts.
Symptoms of P0506
- Check engine light
- High idle
- Low idle
- Rough idle
- Stalling when stopping
- Idle surge
Common causes
- Dirty throttle body
- Vacuum or intake leak
- Idle air control valve fault
- Throttle body adaptation needed
- Damaged wiring or connector
- PCV or intake hose leak
How to diagnose P0506
Steps ordered by urgency — tackle Now items first.
- NowInspect intake hoses, PCV hoses, and vacuum lines for cracks or disconnected fittings.
- NowCheck for carbon buildup around the throttle plate or idle air passage.
- SoonReview live idle RPM, throttle angle, and fuel trim data with a scanner.
- SoonPerform throttle/idle relearn if the battery or throttle body was recently serviced.
- LaterTest the idle air control valve or electronic throttle body after leaks and cleaning are ruled out.
How to fix P0506
Fixes listed in order of likelihood and cost-efficiency.
- 1Clean throttle body
- 2Repair vacuum leak
- 3Perform idle relearn
- 4Replace idle air control valve
- 5Repair wiring or throttle body fault
Want to check your full vehicle?
Run a free maintenance scan to see what else needs attention based on your year, make, model, mileage, and climate.
Estimated Repair Cost — P0506
Ranges vary by vehicle, region, and shop. Use as a ballpark — always get a quote.
DIY estimate
$8 – $25
Shop estimate
$80 – $180
DIY estimate
$10 – $60
Shop estimate
$120 – $350
DIY estimate
$60 – $250
Shop estimate
$250 – $700
Cost data is estimated and may not reflect your specific vehicle or location.
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Frequently Asked Questions
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