Honda Civic P0505 - Idle Air Control System- Failure
P0505 An OBDII Code that addresses the idle air control system within the Honda Civic. It’s a generic code, which means that it has the same meaning for the Civic as it would any other vehicle (Civic or not).
P0505: Idle Air Control System: Malfunction
P0505 usually occurs due to a stuck idle valve, a blocked idle valve control valve, or an unattended vacuum leak. Other causes can also be involved. Although, they aren’t as prevalent.
P0505 Symptoms: Honda Civic
This particular trouble code lets you know that there is something wrong with the idle air control system, but that’s about it. The symptoms may vary.
Below are some symptoms that P0505 is most commonly seen:
- Soon, Service engine light
- Don't be rough
- Very high idle speed
Civic P0505 Causes
P0505 can usually be caused either by a vacuum leak or an issue with the idle control valve. While replacing the idle air control valve seems like a good idea, it’s worth your time to check for a Leakage of vacuum first.
Valve to control the idle airflow
The idle air control valve’s primary job is to regulate the idle speed of your engine. The idle air control valve regulates the engine's idle speed by controlling the amount of air that is allowed in.
It is possible for the IAC to become stuck or dirty. The IAC valve may require a replacement or cleaning may suffice. Here’s a great You Tube video Here are some tips on cleaning an idle valve.
They are available if you decide that an idle valve control valve is needed. Very affordable.
While the idle air control valve is often the cause of P0505, it’s a great idea to start diagnosing it by looking for a vacuum leak. Check the vacuum tubes surrounding the IAC. It may be necessary to replace them if they appear cracked or dry-rotted.
Leakages in the intake manifold and around the throttle body could also cause your Civic to throw this code. Here’s a great article from Popular Mechanics on How to spot a vacuum leak.
Carbon buildup can occur around the IAC's inlet. The problem can be fixed by inspecting the IAC area for carbon-blocking passages.
The throttle body can become too dirty to allow air to enter the engine. You can even throw P0505. Often, when this is the case, you’ll feel the engine stall for a second before it recovers when slowing down.
This happens because the engine can’t adjust to this problem fast enough. This problem is usually solved by cleaning the area around the throttle blades.
It's possible to identify P0505 within your Civic. Most of the time it’s a vacuum leak or the idle air control valve. If you feel like there’s anything that you can add, please feel free to leave a comment below.
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