P0506 Obd2 Code: Idle Air Control System RPM Low

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P0506 Obd2 Code
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An idle control system is a critical part of your vehicle’s overall design and performance. With this technology, you won’t have to worry about your engine stalling while it’s just sitting there, even if you have air conditioning or other power-hungry accessories on.

Do you know what occurs when this system fails? Because of a faulty idle control system, multiple OBD-II codes might be generated. It is one of the most typical error codes a vehicle owner would experience. Exactly what does this mean? Is it feasible to repair it on your own?

Let’s go into the essentials of this code and how to get rid of it.

What does the P0506 OBD-II diagnostic code mean?

What does the P0506 OBD-II diagnostic code mean?

When the idle air control motor and vacuum leaks malfunction, the engine’s performance degrades, resulting in the diagnostic fault code P0506, which means “Idle Speed Control System (ISC) RPM lower than expected.”

As a result, your idle may be lower than your Powertrain Control Module expected, resulting in potentially dangerous driving situations. Different loads and conditions must be dealt with by the PCM/ECU while you drive. 

The ability to maintain a suitable idle is compromised if a leak or malfunction compromises your idle system. The check engine light will come to illuminate if this occurs, indicating that you have a P0506 fault code.

Whenever your vehicle’s idle RPM falls below the pre-determined threshold for an extended period, the MIL will be activated.

Other diagnostic trouble codes

Some of the other error codes:

What Are The Likely Reasons for the P0506 code?

DTC P0506 has many reasons depending on the year, manufacture, and model. These are the most prevalent.

  • Throttle Valve Stuck: Throttle valves are also susceptible to being jammed by carbon deposits. The throttle body is significantly more durable than the IAC and should be cleaned regularly. A replacement isn’t always necessary, but you should still see a specialist to confirm the diagnosis and see if any TSB updates are available.
  • Updated ECU: The idle air control (IAC) may not be present in certain newer automobiles, notably those with electronic throttle bodies. Instead, the primary throttle valve is used to maintain idle speed. Make sure to constantly check with the manufacturer for any prospective recalls, technical service bulletins (TSBs), or upgrades to address idle concerns, regardless of whether you have an IAC valve installed.
  • IAC Stuck: Small solenoids or motors that control the IAC valve aren’t powerful enough to handle the delicate valve. It’s possible that carbon deposits may eventually restrict the valve’s movement. To avoid this, it’s best to keep your valves clean regularly. Remember to replace the gasket, if necessary, before installing a valve replacement.

In order to narrow down your diagnosis, you should look for fuel system lean codes together with the following idle control system issues.

  • PC Idle-Up Switch: An idle-up VSV is a common component of power steering. When the valve detects power steering pressure, it opens a by-pass, letting more air through the throttle body and raising idle speed by a few hundred revs. As long as a valve isn’t working correctly, it will allow air to pass through.
  • Leak Vacuum: Especially in hot environments like the engine compartment, rubber hoses may grow brittle over time. A dozen or more vacuum lines may regulate various systems, from the EVAP to the AC. In most cases, vacuum lines break just where they attach to the nipple, and the damaged section may be easily cut out and reattached. You may have to replace the hose entirely if it becomes brittle.
  • Defective PCV Valve: Anywhere in the crankcase might be affected by a manifold vacuum created by an open PCV valve, such as the dipstick tube or the gasket on the valve cover, which could allow air to enter the engine.

What are the symptoms of a P0506 error code occurrence?

  • Rough engine idle.
  • Check Engine Light is on.
  • Engine idle speed should be reduced.
  • Stopping and starting with no cause or reason.
  • In order to halt, the engine shuts off.

How to diagnose a P0506 error code?

  • All of the PCM’s error codes may be retrieved with an OBD-II scanner P0521
  • When the P0506 diagnostic issue code was created, freeze frame data may be viewed to identify what the engine’s circumstances were at the time.
  • Performs a test drive to check whether the code reappears after clearing the code(s).
  • The data stream will be seen on the OBD-II scanner, and the current engine idle RPM will be compared with the manufacturer’s pre-set idle RPM settings.
  • In order to measure the idle revolutions per minute (RPM) of the engine, switch on the air conditioner and heating heater blower motor. A regular engine idle speed will be tested by putting varied loads on the engine while the PCM is being tested during this step of diagnostics.
  • Checks for vacuum leaks and heavy carbon buildup in the throttle body will need to be cleaned if there is a lot of carbon buildup.
  • Views real-time data from the OBD-II scanner to ensure the proper operation of the idle air control system and PCM.

Is the P0506 code a serious error?

In the event of a loss of power, while driving, the P0506 diagnostic fault code may pose a danger to the driver. Because of this, this code is considered to be of great importance. In the shortest time feasible, the problem should be identified and repaired.

How much money will it take to fix this problem?

Most repair businesses charge between $75 and $150 per hour to diagnose the P0506 error code, which usually takes approximately an hour of work time.

Having identified the root cause of the P0506 error code, your technician should be able to tell you precisely what components are required to resolve the issue, as well as how long it will take. Some issues can be solved quickly, while others need more time and effort.

Professional services have a wide range of prices. It might cost anything from $150 to $500 to replace an idle control valve. However, if your throttle body requires cleaning, expect to pay anything from $226 to $300 for the service.

What kind of fixes is available to repair the error code?

What kind of fixes are available to repair the error code?

To correct this code, there are several options. To find the root source of the issue necessitates a comprehensive diagnosis. Common approaches to this code include:

  • Replace the idle air control valve.
  • The throttle body has to be thoroughly cleaned.
  • Any vacuum leaks should be fixed.
  • A defective throttle body must be replaced
  • Unclog the intake or exhaust
  • Inspect and replace the valve Faulty PCV.
  • Any additional PCM codes may be diagnosed and repaired.
  • Replace the steering pressure switch.
  • It is necessary to replace the idle air control motor.
  • Replacing or reprogramming the PCM is an alternative.
  • Remove obstructions from the intake or exhaust


The P0506 error code is a serious problem that should be addressed immediately. If you’re not confident in your ability to remedy the problem using the procedures and advice I provided, your best option is to take your car to a respected technician. If you need assistance or more advice on how to prevent running into the same problem again in the future, don’t hesitate to contact a nearby auto repair shop.