6 Symptoms of P0505 Code

When you see a P0505 code, it means there’s an issue with the idle air control system. The idle air control system helps your engine run at a consistent RPM speed in modern vehicles. It ensures your vehicle stays running when you come to a stop (like at a red light) and that it doesn’t stall when you take your foot off the gas pedal.

The P0505 code specifically indicates there’s an issue with the idle air control valve or its circuit. For example, if the valve gets stuck in an open or closed position, it can cause your engine to stall.

P0505 code

The idle air control system manages the amount of air that goes into the engine when it’s idling, so it can help keep a constant idle speed. A P0505 code means there is an issue with the system, which could be due to a faulty sensor, malfunctioning actuator, or a faulty wiring connection in the idle air control circuit.

If your vehicle has a P0505 code, it’s important to get it fixed right away because not only will this affect how smooth your ride is, but it could also cause other issues if you don’t address it right away.

6 Symptoms of P0505 Code

Several symptoms can be associated with the P0505 code. However, it is important to note that you’ll find the most common symptom is engine hesitation when the vehicle is being accelerated.

Many minor symptoms may be linked to this problem; however, a check engine light will not always illuminate, and there will rarely be a noticeable reduction in fuel efficiency.

When a P0505 code comes up, you’ll notice symptoms like:

1. Intermittent stalling

Intermittent stalling can result from a variety of problems, including a faulty mass airflow sensor (MAF). If a P0505 code is triggered after replacing the air filter, installing a new MAF or throttle body, or adjusting the idle air valve with no improvement, the problem may be harder to fix.

The easiest solution is to have the vehicle’s computer scanned, and the fault code(s) read so that they can be cleared.

2. Engine might not start due to a lack of fuel

Your engine may not start while driving or when you are ready to go, or you may experience rough idle. You may also see a Check Engine Light with the code P0505 displayed.

If any of these symptoms sound familiar, your fuel injectors might be clogged, or your fuel pump may not be working at full capacity. This issue can be worsened by poor fuel quality.

3. Poor fuel economy

Your vehicle uses a portion of the fuel that is supplied to it to cool down the ECM and the injectors while they work. Too much heat can cause these systems to fail, which can cause poor performance. The ECM detects this condition using its built-in temperature sensor.

A code P0505 may be set for this condition but will more than likely be set in combination with many other codes relating to fuel delivery, emission control, or engine misfire.

4. Poor acceleration

When you get a “P0505” error code on your GMC Sierra 1500 truck, it means the Camshaft Position – Bank 1 Sensor A has failed. This will cause poor acceleration and rough idle and may even prevent the vehicle from starting.

The Camshaft is responsible for opening the intake and exhaust valves when the engine is running. The camshaft sensor indicates to the PCM that these valves are open or closed at various points during engine operation.

5. Car will not idle

Problems with the idle air control valve can create a myriad of issues. When it’s not working properly, the constant flow of air doesn’t allow the throttle body to close or function properly.

The result is that you experience a loss of power, and if the problem persists, stalling out may occur. If one of these symptoms happens to you, check your idle air control valve.

6. A check engine light that won’t go out

A P0505 code indicates communication issues between the engine computer and the vehicle’s mass airflow (MAF) sensor. While this does not pose a safety risk in and of itself, it does cause the check engine light to come on and remains on until the issue is resolved.

P0505 code

Causes of P0505 Code

Code P0505 is a very common code for the Check Engine Light and is caused by a sensor in the emissions system. There are multiple components of the emissions system, including catalytic converters, O2 sensors, vapor recovery systems, and other devices that monitor and control engine emissions.

The P0505 code is displayed when the PCM (Powertrain Control Module) detects the engine knocking. Causes for this code may include Worn spark plugs, Low engine oil level, and an Intake Manifold Runner Control (IMRC) problem.

Can I drive with a P0505 code?

A P0505 code means that your catalytic converter has failed. As long as you are not getting other codes as well, this could be okay to drive, but it may damage your engine with time. If you want to be sure that your engine is ok, I would have a mechanic check out the car.

Yes, you can drive with the P0505 code. Infrequent use with normal driving conditions may cause this code to come and go. There is no need to have your vehicle towed to a repair shop. However, if the P0505 code was caused by a more serious electrical problem that has been fixed but occasionally re-appears, your vehicle should be inspected by a technician who is experienced with these types of issues.

How do I reset my idle air control valve?

Resetting your idle air control valve is a great way to increase horsepower in your engine quickly. The idle air control, or IAC, cuts down on the amount of fuel being pushed into the engine when not needed. While this is good in terms of emissions, we have found that leaving it set at the factory defaults can hurt performance.

To reset the valve, proceed to the engine bay and locate the little green idle air control valve. It is often taped to a hose, so look carefully. In most cases, you will simply pull up on the top tab with moderate force until it pops back down and is flush again with its body.

This will be a bit easier if you loosen the nut just above one of the tabs first and let it fall slightly down towards you. The hardest part is pulling up on it and holding it while you re-tighten and hold the nut on top (which involves both hands since you will likely have to hold up on the valve again after locking in place). Once done, start up your vehicle and enjoy the immediate roar of power.

How do I fix my idle air control?

The idle air control regulates the amount of air that is injected into the engine, which helps keep it at a steady rpm (revolutions per minute, how fast the motor turns). This is all electronically monitored and controlled. There are generally two ways to fix this, either physically replace the part yourself, or have it done professionally.

Can I drive with a failing idle air control valve?

Yes, you can drive your car with a failing idle air control valve (IACV). The IACV is the primary way that the engine computer harness reads and, if necessary, adjusts the engine idle speed. Although it is possible, it is not really recommended by any manufacturer because it can sometimes warp your engine’s valves, pistons, and liners as well as cause stress to some other parts of your car.

If there are no other options and you must drive your car, then it is suggested that you drive no more than 40 miles per hour (64.4 km/hr.). This avoids any unnecessary strain on your engine components. Most places recommend you have the IACV replaced immediately after noticing any signs of failure, such as extra noise or difficulty starting.

How much does it cost to fix an idle air control valve?

For this job, I would expect a typical mechanic to charge between $90 and $120. Although it is possible for some mechanics to come in under that price, it is unlikely because of the amount of labor required. Of course, if you have access to the correct tools (and don’t mind doing some work yourself), this may be an option for you.

What happens if the idle air control valve is stuck open?

If the idle air control valve is stuck open, this will cause the engine to run rich. This means that the engine will not be getting enough air. Enriching the mixture gives more fuel but detracts from power.

In addition to affecting power, running too rich can lead to a variety of problems, including increased emissions, higher fuel consumption, fouled spark plugs, and damaged pistons.

What are the symptoms of a faulty idle air control valve?

You may be experiencing one of the following symptoms if your IAC valve is acting up: Your vehicle’s engine is cranking, idling, and running rough, such as vibrating and stalling. Your check engine light may come on after you perform a short drive. You may hear a rattling sound near the throttle body or in the intake manifold. These noises are usually more prevalent when your car is warm.

Can an idle control valve be cleaned?

An idle control valve can be cleaned in many cases by spraying it out with an aerosol cleaner or with a washdown. Be sure the idle control valve is off, turn off the vacuum and open the throttle stop.

You will need to clean off both sides of the rotor shaft inside and outside the bell housing, depending on how bad the buildup is. If you want to clean and inspect it further, you can also remove the rotor shaft and clean it with a solvent like a brake cleaner or carburetor brush cleaner.

Conclusion

That P0505 code means there may be a broken wire at the accelerator pedal position sensor. When this happens, the wire gets so hot that it melts or shorts out or just plain breaks. This can temporarily disable your cruise control.

A short in this wire will also cause intermittent operation of your cruise control until you replace the damaged part. That P0505 code can also show up due to a faulty camshaft position sensor as well. To get this fixed right away, a certified mechanic will help to diagnose the cruise control problem and replace any needed parts.