P0506
Fix within 1-2 weeksYour engine's idle speed is lower than the computer expects, causing rough idle or stalling.
Code P0506 means your engine's idle RPM is lower than expected. Common causes: Dirty throttle body (45%), faulty IAC valve (30%), vacuum leaks (15%). Drivability: Yes, but fix within 1-2 weeks due to stalling risk. Repair cost: $50-$200 DIY, $150-$500 professional.
Can I Drive With P0506?
Yes, for short trips only
Essential trips under 10 miles, avoid highways and heavy traffic where stalling is dangerous.
Stop driving immediately if: Flashing CEL, engine stalls frequently, or you experience significant power loss.
Symptoms of P0506
- 1Engine idles roughly or shakes
- 2Engine stalls when coming to a stop or in neutral
- 3Engine dies immediately after starting
- 4Difficulty starting the engine
Common Causes of P0506
Parts most likely causing this code, ranked by probability
Carbon buildup around the throttle plate restricts the small amount of air needed for a stable idle.
45% of P0506 cases are fixed by cleaning the throttle body
A faulty or carbon-clogged IAC valve cannot properly regulate the amount of air bypassing the throttle plate at idle.
30% of P0506 cases are fixed by replacing or cleaning the IAC valve
Unmetered air entering the engine causes a lean condition, forcing the engine to struggle and lower its idle speed.
15% of P0506 cases are fixed by repairing a vacuum leak
Damaged wiring or a loose connector to the IAC valve or electronic throttle body prevents proper idle control.
5% of P0506 cases are fixed by repairing electrical connections
For vehicles without a separate IAC valve, a failing electronic throttle body motor or sensor cannot maintain the correct idle position.
5% of P0506 cases are fixed by replacing the electronic throttle body
Check These First (Before Buying Parts)
- Visually inspect all vacuum hoses for cracks, disconnections, or damage.
- Listen for any hissing sounds around the engine bay that indicate a vacuum leak.
- Check the air filter to ensure it is not excessively dirty and restricting airflow.
How to Diagnose P0506
- 1Visually inspect all vacuum hoses for cracks, disconnections, or damage.
- 2Remove and thoroughly clean the throttle body and, if present, the Idle Air Control (IAC) valve with throttle body cleaner.
- 3Check the electrical connector and wiring to the IAC valve or electronic throttle body for corrosion or damage.
- 4With the engine running, listen for hissing sounds around the intake manifold and vacuum lines, indicating a leak.
- 5If available, use a scan tool to monitor live data for IAC valve position or throttle plate angle at idle.
P0506 on Popular Vehicles
Honda Accord
1998-2002These models are particularly prone to P0506 due to carbon buildup or failure of the dedicated Idle Air Control (IAC) valve. Cleaning or replacement is a very common fix.
70% fixed by cleaning or replacing the IAC valve
Toyota Camry
1997-2001Similar to Hondas of this era, older Camry models often experience P0506 from a dirty or failing IAC valve. Throttle body cleaning is also a strong contender.
65% fixed by cleaning or replacing IAC valve/throttle body
Ford F-150
2004-2024For many F-150s, especially those with higher mileage, P0506 is frequently resolved by a thorough cleaning of the electronic throttle body, which can accumulate significant carbon.
50% fixed by cleaning the throttle body
Frequently Asked Questions
What does P0506 mean?
P0506 indicates that your vehicle's engine control module (ECM) or powertrain control module (PCM) has detected that the engine's idle speed is consistently lower than its programmed target RPM.
Can I drive with P0506?
Yes, you can drive with P0506, but you must fix it within 1-2 weeks. The primary risk is the engine stalling unexpectedly, especially when coming to a stop, which creates a safety hazard. Address this code promptly to prevent potential accidents.
Will P0506 clear itself?
No, P0506 will not clear itself. The underlying issue causing the low idle, such as a dirty throttle body or a faulty IAC valve, requires a physical repair or cleaning. The code will persist until the problem is resolved.
How do I fix P0506 myself?
Start by inspecting all vacuum lines for damage. Then, remove and thoroughly clean your throttle body and, if your vehicle has one, the Idle Air Control (IAC) valve using a dedicated throttle body cleaner. Check the electrical connections to these components. If cleaning does not resolve the issue, you may need to replace the IAC valve or the electronic throttle body.
How much does it cost to fix P0506?
DIY repair costs for P0506 range from $50 to $200, primarily for throttle body cleaner or a new IAC valve. Professional shop repairs typically cost $150 to $500, covering diagnosis, cleaning, and potentially part replacement.
P0506 keeps coming back - why?
P0506 keeps coming back because the root cause was not fully addressed. This often happens if a vacuum leak was missed, the throttle body or IAC valve was not cleaned thoroughly enough, or a faulty electronic throttle body was not replaced. A deeper diagnostic check is necessary to pinpoint the exact issue.
Will P0506 fail emissions/smog test?
Yes, P0506 will cause your vehicle to fail an emissions or smog test. A check engine light illuminated for any reason, including P0506, is an automatic failure in states with such inspections.
What's the difference between P0506 and P0507?
P0506 indicates that the engine's idle speed is *lower* than expected, often leading to stalling. P0507 indicates that the engine's idle speed is *higher* than expected, which can be caused by a stuck open IAC valve, a large vacuum leak, or a faulty electronic throttle body.
P0506 on Honda Accord?
On many older Honda Accord models (e.g., 1998-2002), P0506 is frequently caused by a dirty or failing Idle Air Control (IAC) valve. Cleaning or replacing the IAC valve is a very common and effective fix for this code on these vehicles.
Questions to Ask Your Mechanic
Did you check for vacuum leaks around the intake manifold and all vacuum lines?
Good answer: Yes, I performed a smoke test and visually inspected all hoses. I found no leaks.
What did you find when inspecting the throttle body and IAC valve?
Good answer: The throttle body was heavily carbonized, and the IAC valve was sticking. I cleaned both thoroughly.
Repair Cost Estimate
DIY Repair
Parts only
$50-$200
Shop Repair
Parts + labor
$150-$500
Save $100-$300 by doing it yourself
Difficulty
intermediate
Time
1-2 hours
Intermediate - Cleaning the throttle body and IAC valve is beginner-friendly, but diagnosing vacuum leaks or replacing an electronic throttle body requires a bit more mechanical comfort and potentially a scan tool.
Cost of Waiting
Ignoring P0506 leads to frequent engine stalling, which is a significant safety hazard, especially in traffic. Repeated stalling also puts extra strain on your starter motor and battery, potentially leading to additional repairs. A simple $10 throttle body cleaning now prevents a $500 tow and potential accident later.
While You're In There...
If you remove the throttle body for cleaning, replacing the gasket prevents future vacuum leaks in that area. It's low cost and the labor is already done.
A clean air filter ensures proper airflow to the engine, which is crucial for stable idle. It's often accessed when working near the throttle body.
While not a direct cause of P0506, a dirty MAF sensor can affect air metering and engine performance. Cleaning it is a quick, low-cost step while working on the intake system.
Tools You'll Need
- Socket set
- Screwdrivers
- Throttle body cleaner
- Multimeter (optional, for testing IAC valve)
P0506 is a common code related to engine idle control. Most repairs are straightforward, often involving just cleaning, and your engine will run smoothly afterward.
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Your Next Steps
Step 1: Visually inspect all vacuum lines and listen for leaks. Repair any damaged hoses or connections.
Step 2: If no vacuum leaks are found, remove and thoroughly clean the throttle body and, if present, the Idle Air Control (IAC) valve. Reassemble and test.
Step 3: If cleaning doesn't resolve the issue, you likely need to replace the faulty Idle Air Control (IAC) valve or, for newer vehicles, the entire electronic throttle body. Parts you'll likely need: Throttle body cleaner, new IAC valve (if applicable), or a new electronic throttle body.