Код p0456 ford

Содержание

• Код P0456 Определение
• Что означает код P0456?
• P0456 Симптомы кода неисправности
• Причины появления кода P0456
• Насколько серьезно код P0456?
• Какой ремонт может исправить ошибку P0456?
• P0456 Общие ошибки диагностики
• Как диагностировать код неисправности P0456
• Расчетная стоимость ремонта P0456
• Связанные коды неисправностей P0456
• Общие вопросы, связанные с P0456
• Что вызывает код P0456?
• Что означает P0456?
• Как очистить код P0456?
• Как исправить код P0456?

Код неисправности P0456 появляется в блоке управления двигателем, когда в вашей системе EVAP есть небольшая утечка.

Причин этого может быть много, и в этом руководстве вы узнаете все, что вам нужно знать о коде P0456.

Facts about P0456 Code – Evaporative Emissions System Small Leak Detected:

1. P0456 is an OBD-II generic code that indicates the ECM has detected a very small leak in the evaporative system during vehicle off-testing.
2. The test has to fail twice in a row to cause the code to be activated by the ECM.
3. The cause of code P0456 can be a small leak at any of the system components or hose connections.
4. The two most common causes of the code are the gas cap vent and the purge vent valve, which will not seal completely.
5. Symptoms of the P0456 code include the Check Engine Light illuminating and the code being set in ECM memory.
6. To diagnose the P0456 code, a mechanic will scan codes, inspect the entire vapor purge valve system, check the purge control valve, and perform a smoke leakage test on the fuel vapor system.
7. Common mistakes when diagnosing the P0456 code include assuming the purge control valve is defective without doing a thorough diagnostic of the complete system and not verifying the leak and replacing parts that may or may not be the problem.
8. The P0456 code can cause the Check Engine Light to go on, which will cause a failed emission test.
9. The code means the fuel vapor system has a very small leak, and the ECM monitors will not pass emissions if the leak is not found.
10. Repairs that can fix the P0456 code include replacing a leaking gas cap, replacing the leaking or clogged purge vent valve, and replacing a leaking purge valve.

На каких автомобилях чаще встречается данная проблема

Проблема с кодом P0456 может встречаться на различных машинах, но всегда есть статистика, на каких марках эта ошибка присутствует чаще. Вот список некоторых из них:

• Audi (Ауди ТТ)
• BMW
• Chrysler (Крайслер Вояджер)
• Dodge (Додж Дакота, Интрепид, Калибр, Караван, Неон, Рам, Стратус)
• Ford (Форд Фокус)
• Hyundai (Хендай Генезис, Элантра)
• Isuzu (Исузу Родео)
• Jeep (Джип Вранглер)
• Lexus (Лексус gx470, lx470)
• Mazda
• Mercedes
• Mitsubishi (Митсубиси Аутлендер, Галант, Монтеро)
• Nissan
• Subaru
• Suzuki
• Toyota (Тойота Камри, Сиенна)
• Volkswagen (Фольксваген Пассат)
• Volvo (Вольво xc90)

С кодом неисправности Р0456 иногда можно встретить и другие ошибки. Наиболее часто встречаются следующие: P0004, P0420, P0440, P0441, P0442, P0443, P0444, P0445, P0446, P0447, P0448, P0449, P0450, P0451, P0452, P0453, P0454, P0455, P0457, P0458, P0459, P1684.

How To Diagnose An p0456 Code?

The best way to check for leaks in any vacuum system is by performing a smoke test. 

By running smoke through the closed system, you can shine a light on the gas tank or charcoal canister and find out exactly where the leak is because there will be smoke coming out of it. 

The purge control valve is either next to the charcoal canister underneath the vehicle or under the hood of the vehicle.  

It can be disconnected for access to the system and tested with a smoke machine. 

Most mechanic shops are equipped with smoke testers to handle this situation easily when it arises. 

Here are the basic steps to diagnosing a p0456 code:

P0456 Dodge: Causes And Diagnostics

The P0456 code tells you what’s wrong with the car, but it won’t tell you exactly what’s causing it. In this case, we know that there’s a leak in the EVAP system, but we’re going to have to find the source of that leak as well. Here are the potential causes:

1. Loose gas cap. You might not have tightened the gas cap properly after your last fill-up, so check if the gas cap is loose. If it’s tight, then something else is triggering the code.
2. Leaking or disconnected EVAP hose.
3. Faulty or leaking purge canister or solenoid (control valve).
4. Fuel tank leak. This is less likely but should be easy to check, locate the fuel tank underneath your car and inspect if there’s fuel leaking out of it.

So, those are the possible causes that can trigger the P0456 code. We’ll also discuss how to diagnose it, but there is one common culprit for the P0456 code in Dodge cars:

Common Cause For P0456 In Dodge

We’re not sure why it often fails. But it’s most likely some sort of engineering flaw or oversight during the design process of the device. This failure seems to affect mostly early 2000s Dodge cars, although later models are often affected as well. If you have a P0456 code in your Dodge, this is the most common culprit according to many owners.

The video above from BoostedMotorsports should give you a good idea of how to locate the device, remove it, and then replace it, especially if you have a Ram truck. In most cases, it’ll be underneath the car near the rear differential. Check your car’s service manual if you have difficulties locating the device.

After you remove the ESIM, you can test it out first to see if it’s faulty. Here’s what you need to do:

1. Connect a multimeter to the electrical pins of the ESIM.
2. Blow the ESIM through its valve, and inspect the multimeter’s reading.
3. It should read about 12 volts, if there’s no reading or it’s really low, then you have a faulty ESIM.

This is the most common culprit for EVAP-related codes in Dodge cars. It seems to be a badly-designed and unreliable product, so we recommend checking the ESIM first. If the ESIM is fine, here’s how to diagnose the rest of the EVAP system:

Step 1 – Check For Other Trouble Codes

For example, the P0445 code is another EVAP-related code. However, this code usually indicates an issue with the purge control valve, although it may also be there because of a loose gas cap. Anyway, if you see this code as well, then that narrows down your leak issue with the purge control valve and that’s what you should inspect next.

If no other codes are present, then it’s time to do a visual inspection:

Step 2 – Visual Inspection

Inspect all the EVAP system components and hoses and see if you can find any physical leaks. This includes inspecting the hoses, the purge canister, the valves, and checking your fuel tank for leaks as well since that can also trigger the P0456.

The video above from 1A Auto is a great guide on how to check for physical leaks on the EVAP system. Of course, the location of the components will vary depending on your car’s make and model. If you have difficulty locating the components, check your car’s service manual.

Some components may not show signs of damage, such as the purge control valve. In this case, you need to test the device:

Step 3 – Testing The Purge Control Valve

Testing this device is fairly straightforward:

1. Locate and remove the purge control valve. This is usually a black plastic device that sits near the car’s air intake hoses. Check your service manual to help locate the device.
2. The car has to be off when you remove it. Disconnect its electrical connectors, then undo the bolts holding it down and remove the device.
3. Blow into the valves of the device. If air goes through the other end, then your purge valve is stuck open which causes a leak in the system.

Finally, if all the components seem fine, you can do a smoke test to help you detect the leak. Sometimes the leak is so small that you can’t see it, and a smoke test will help you detect the leak.

Step 4 – Smoke Test

Note that this test will require a smoke machine. They can cost thousands of dollars, and it’s not something that your local auto parts store is likely to have to rent. So, unless you already own one or you have access to one, you’re going to have to ask an auto repair shop to do it for you. That being said, here’s how to perform the test:

P0456 Dodge Code Severity Level

Severity Level: Low to intermediate – Get fixed soon but you can continue driving until then

The only system that the P0456 deals with is the EVAP, which in and of itself does not affect drivability. The only thing that will suffer from an P0456 code is there will possibly be increased emissions output from your vehicle. It will not hurt drivability and will not hurt your engine if you drive with it malfunctioning. Also, this code is for a small leak in the EVAP system, which obviously is less severe than a DTC for a big leak.

However, while your car will drive okay, you may see an increase in fuel consumption, as some of it may be leaking. In addition, the emissions being released contribute to climate change, increasing the likelihood of extreme weather events and thus reducing the amount of days your car can rip up the blacktop.

While you don’t have to pull over right away if you get the P0456 code, you should get it taken care of in a timely fashion. It’s also important to keep in mind your vehicle will not pass emissions testing with an EVAP DTC. If you need to register your car with an emissions test, you will need to clear and fix your EVAP DTCs if they are present.

Проявление ошибки P0456, симптомы

при указанной несиправности на приборной панели автомобиля загорится индикатор Check Engine и в памяти ECM сохранится ошибка P0456.

Как сканером прочитать ошибку P0456?

При диагностировании данного кода ошибки диагност выполнит следующее

• Считает все данные и коды ошибок, сохраненные в памяти ECM, с помощью сканера OBD-II;
• Проверит клапаны продувки и вентиляции, а также шланговые соединения на наличие повреждений;
• Проверит клапан вентиляции на предмет засорения грязью, мусором или паутиной, что может привести к тому, что клапан будет работать ненадлежащим образом;
• Проведет испытание на герметичность с помощью дыма, чтобы выяснить, присутствует ли утечка в системе улавливания паров топлива, а также попытается устранить причину возникновения утечки. Проверит, хорошо ли затянута и не повреждена ли крышка топливного бака;
• Проверит работу клапана продувки, чтобы выяснить, способен ли он удерживать вакуум.

Общие ошибки при диагностировании кода P0456

• Уверенность в том, что причиной возникновения ошибки является неисправность клапана продувки, в то время как проблема заключается в повреждении или обрыве электрических проводов;
• Пренебрежение выполнением проверки на предмет утечки и ошибочная замена исправных деталей,;
• Не обращение к техническому сервисному бюллетеню от автопроизводителя, в котором могут быть указаны способы устранения ошибки.

Если появилась ошибка P0456, чем это грозит?

• При появлении ошибки P0456 на приборной панели автомобиля загорится индикатор Check Engine и автомобиль, скорее всего, не сможет пройти проверку на токсичность отработавших газов;
• Данный код ошибки указывает на наличие очень незначительной утечки в системе улавливания паров топлива, которую в некоторых автомобилях будет сложно обнаружить. Ошибка P0456 будет появляться до тех пор, пока утечка не будет обнаружена и устранена;
• Если индикатор Check Engine погаснет, но утечка не будет обнаружена и устранена, автомобиль все равно не сможет пройти проверку на токсичность отработавших газов.

What does that mean?

This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to OBD-II equipped vehicles. Although generic, the specific repair steps may vary depending on make/model.

The Powertrain Control Module (PCM) at different times performs various tests
on the EVAP system. OBD II Enhanced EVAP systems are in place to keep fuel tank
vapors from venting into the atmosphere, and instead purges them into the engine
to be burned.

Regular pressure tests are conducted by the PCM to monitor the
sealed system for leaks. The PCM monitors the EVAP system pressure by watching
the fuel tank pressure (FTP) sensor. When the sensor indicates a small leak
in the EVAP system, this code is set.

Related evaporative emission trouble codes include P0450, P0451, P0452, P0453, P0454, P0455, P0457, P0458, and P0459.

Grand Cherokee P0456 Trouble Code Causes + Diagnosis

There are many things that can cause the P0456 trouble code to trigger in your Jeep Grand Cherokee. If your Grand Cherokee has warned you at all in the last few months that the fuel cap was off when it wasn’t, then replacing it would be a great first step.

Here are the most common problems that will throw the code, presented in order (somewhat) from most to least likely:

Fuel Cap

Your Grand Cherokee’s fuel cap prevents fuel vapor from escaping the fuel tank.  If the gas cap has failed, you’ll likely get a message informing you that the fuel cap is off even when it is on. If you are getting that message, plus a P0456, replace the fuel cape.

Evap System Hose

The EVAP hose that carries the fuel vapor from the fuel tank to the intake manifold can begin to leak. This will cause the P0456 code. Look for either a tear or a hole in it. This is one of the most common issues that cause this code.

Vapor Canister Purge Valve

Purge valves come in many shapes and sizes

One of the most common causes of the P0456 code is the vapor canister purge valve. It’s really easy to replace. There are a few clips that you need to find and remove. Your Grand Cherokee’s purge valve location and style will depend on the model year and engine equipped.

Fuel Tank Sending Unit

It is possible for the gasket that attaches the fuel-sending unit to the gas tank to go bad. This can reduce tank pressure and throw the code.

Fuel Filler Neck

There is often a gasket where the fuel filler neck connects with the gas tank. This gasket can dry out, especially with vehicles that spend their time in dry climates. When it dries out, the fuel tank can’t hold pressure anymore. 

A leaking fuel tank can also cause P0456 in the Jeep Grand Cherokee, but it’s not as common as a bad fuel filler neck or sending unit.

DTC P0456 Dodge Code Meaning

The P0456 Dodge code indicates “Evaporative Emission Control System (EVAP) Small Leak Detected”. The code corresponds to your car’s EVAP system. The EVAP system’s purpose is to help reduce emissions by preventing gasoline vapors from exiting your fuel system and fuel tank.

The basic run down of the EVAP system is as follows. Fuel vapors accumulate in your fuel tank over time, and they are absorbed by your charcoal canister, which acts like an absorbent filter. Also part of the EVAP system is the vent valve, which allows outside air into the charcoal canister.

After the charcoal canister is full of gas vapors, the vapors are sent through EVAP lines from the charcoal canister on the fuel tank to the intake manifold. The vapors are then released back into the manifold through a purge valve, so they can be burned inside the engine instead of being released to the atmosphere. While this isn’t ideal for performance, it massively reduces bad emissions outputs.

If your car is showing a P0456 Dodge DTC, it means that somewhere in your EVAP system there is a leak. All parts of the EVAP system are controlled by your ECU. As part of its normal functions, the ECU performs tests on the EVAP system to make sure it is functioning properly and not leaking. If your EVAP system fails the test a DTC code appears, often the P0456.

This particular code indicates that the leak is small rather than big, so it’s not a huge immediate concern.

P0456 Dodge Signs

Here are some signs that you might notice when you have a P0456 code in your car. Note that this applies to cars other than Dodge as well:

1. Poor Fuel Consumption

As mentioned, the EVAP system can help to improve fuel mileage in your car. This is because by using that recaptured fuel vapors, your car can reduce its fuel usage and use the vapors instead at certain times.

If you leak the EVAP, this means your car isn’t capturing as much fuel vapors as it normally would if at all. So, your car will be using less of that vapor, and use more fuel. However, the effect is likely minimal to the point where you might not notice it.

As far as we can tell, there has been no research done to tell how much the EVAP system affect MPG, so there’s no telling how much worse your fuel consumption will get worse. Unless your car has an MPG monitoring system, it’s unlikely you will notice the effect.

2. Fuel Smell

Perhaps the most likely sign you will notice is the smell of fuel inside the car. Since the leak would allow fuel vapors to escape into the open air, you’ll likely smell it while driving.

Regardless of the cause, the smell of fuel while driving is concerning. The best-case scenario is that it’s the fuel vapors escaping the fuel tank. The worst-case scenario is that you have a fuel leak somewhere and it could start a fire.

You’ll want to find out where the smell is coming from and address it. Best do it as soon as possible before your car turns crisper than burnt bacon—or worse.  Some other possible causes of fuel smell while driving include a loose fuel tank cap, fuel line leaks (you’ll likely see fuel dripping down underneath your car), and loose fuel injectors.

That last one is particularly dangerous since the spark plug could ignite the fuel outside of the combustion chamber, starting a fire. Forget the check engine light, your engine will light up altogether. Jokes aside, we can’t stress this enough: do not ignore the smell of fuel inside your car.

3. Your Car Fails To Pass Emissions Test

Emissions test frequency varies by state. Some states require it every two years, others require it every year. Some states require it for every car, others will exempt cars than less three years old. We recommend checking with your local DMV office to find out when you need to do emissions testing for your car.

Anyway, since the EVAP system is part of the emissions control system, your car will likely fail an emissions test. Even if you don’t care about the environment, this means you’re going to have issues with registration. So, you’re going to want to address this issue.

Jeep Grand Cherokee P0456 Definition: EVAP Leak (Small)

P0456 is a universal OBD II trouble code. This means that regardless of vehicle make or model, the code will mean the same thing (Grand Cherokee or not). The code technically stands for evaporative emission system small leak detected.

Evaporative Emissions System 

The EVAP system captures all fuel vapor from the fuel tank and sends them to the engine’s intake to be ignited during the normal combustion process.  Its primary function is emissions reduction. 

Small Leak

A small EVAP leak should not change the way your engine runs nor be considered a breakdown risk.

When there is a small leak in the Jeep Grand Cherokee’s EVAP system, it will throw the P0456 OBDII Code. If there is a large leak, it’ll throw P0455.

P0456 Dodge: EVAP Issues Explained

The Evaporative Emission System or EVAP for short is one of several emissions control devices in your car (to learn more, check out our guide on what is the catalytic converter). Most cars since the ’80s are likely to have all six of these emissions control devices:

1. Positive Crankcase Ventilation (PCV) system.
2. Evaporative Emission Control (EVAP) system.
3. Exhaust Gas Recirculation (EGR) system.
4. A secondary air injection system
5. Catalytic converter.
6. Exhaust pipes.

Of course, we’ll focus on that EVAP system. Before we get into the causes and signs, here’s how the EVAP system works and what it’s for so you can get a better understanding:

How The EVAP System Works

The EVAP system is essentially a device that captures gas (fuel) vapors from the fuel tank. This device captures fuel vapors and prevents these toxic vapors from escaping into the environment. Hence why it’s considered a part of the emissions control system. Here’s how it works:

Afterward, when the Engine Control Unit (ECU) demands it, it will open the purge valve. This valve will allow the vapor to escape from the charcoal canister. The engine will then draw these vapors and injects them into the engine’s cylinders to be used as fuel.

Why Is The EVAP Necessary?

As mentioned, it’s necessary to control the emissions that a car produces. In the 1960s, smog resulting from car emissions was becoming a real problem. It was particularly bad in California, a state with a large population and where almost everyone drives.

Needless to say, smog is harmful to the environment and your health. To combat this problem, many emissions control devices started becoming mandatory. And California is often the first state to introduce laws mandating carmakers to fit their cars with certain emissions control devices, including the EVAP system in 1970.

So, it’s largely for environmental reasons. Cars without an EVAP system or other mandatory emissions devices will not pass DOT standards, let alone be allowed to go on sale in the US. And if you have a faulty EVAP system, chances are it won’t pass an emissions test.

Additionally, recirculating the fuel vapors helps to improve fuel consumption albeit slightly. This brings us to our next section:

Related P0456 Dodge DTCs

Here is a list of all DTCs related to the Dodge P0456 Code:

• P0442 – Evaporative Emission Control System Leak Detected (Small Leak)
• P0455 – Evaporative Emission Control System Large Leak Detected
• P0457 – Evaporative Emission Control System Leak Detected (Fuel Cap Loose/Off)

There are nearly 30 DTC for the EVAP system on a Dodge alone. The DTC for the EVAP system starts with a P0440 and goes through P0469. The majority relate to either the purge control valve or vent control valve. There are also several other EVAP DTCs specifically for leaks.

As you can see, the P0442 and P0455 are almost identical to the P0456 Dodge code. The P0442 usually means there is a vapor leak, and the P0455 indicates that there is a large leak. The P0457 indicates that the leak is most likely coming from the gas cap not being secured. It is possible to get multiple DTC for the EVAP system at the same time, sometimes due to the same issue.

It is similar to the P0441 Toyota Engine Fault Code we covered previously.

How Much Does It Cost to Fix Toyota Code P0456?

P0456 can be caused by anything from a loose gas cap to a faulty valve to a leaking fuel tank. It’s impossible to give an accurate estimate without properly diagnosing the issue first. 

If you take your car to a shop for diagnosis, most shops will start with an hour of “diag time” (the time spent in labor diagnosing your specific issue). Depending on the shop’s labor rate, this typically costs somewhere between $75-$150. Many, if not most, shops will apply this diagnosis fee to any required repairs if you have them perform the repairs for you. From there, a shop will be able to give you an accurate estimate for repairs to fix your P0456 code.

Possible Repair Costs for Toyota P0456

For error code P0456, one or more of the below repairs may be needed to solve the underlying issue. For each possible repair, the estimated cost of repair includes the cost of the relevant parts and the cost of labor required to make the repair.

• Gas Cap $20-$60
• Evap Purge Volume Control Valve $150-$200
• Charcoal Canister Vent Control Valve $150-$200
• Replacement Evap Line $50-$100
• Charcoal Canister $200-$600

P0456 Dodge Repairs & Cost

Hopefully, the steps above have helped you how to diagnose and find the cause of the P0456 code in your Dodge. Now, here are the repair costs:

1. Gas cap replacement. If you have a bad gas cap, replacing it may fix the issue. This costs up to $60 in most cars.
2. Charcoal Canister Vent Control Valve. This costs between $80 and $200 depending on the car’s make and model including labor. The part itself usually costs no more than $120.
3. Charcoal Canister replacement. The charcoal canister itself might be bad, in which case you’ll need to replace it. It costs between $200 – $600, but we found that in the Dodge Challenger it’s estimated to cost no more than $239 (especially among the best Dodge Challenger years).
4. Replace EVAP line and hoses. Replacing the EVAP system’s hoses usually cost no more than $100 including labor, as the hoses and lines themselves are not very expensive, to begin with. But it may be more than depending on how many lines you need to replace.

On average, you can expect to pay somewhere between $150 – $300 to repair a P0456 code. The most expensive job is usually replacing the charcoal canister. But as mentioned, according to YourMechanic the Dodge Challenger costs $239 on average to replace the canister. So it’s still relatively affordable.

Most of the replacement jobs are relatively easy, and you can do it yourself to save some money. But if you’re not sure about your skills or you have butterfingers, better leave it to professionals to avoid any further damages or issues.

Common Symptoms of P0456 Code

The most common symptoms of the P0456 Dodge code are:

• DTC for the EVAP System
• Check Engine Light
• Decreased fuel economy
• Smell of fuel inside cabin
• Smell of emissions inside cabin

For the most part, you won’t see any drivability changes if there is a problem with your EVAP system. Most people do not even realize there is an issue present until the check engine light comes on and the DTC is checked.

You might notice a small scent of fuel due to it potentially leaking from the charcoal canister, or you might smell the rotten odor of unfiltered emissions escaping the fuel system, too. Besides that and the DTC, there is really no way to tell if you have an EVAP leak.

DIY Steps to Diagnose Toyota Code P0456

Toyota engine code P0456 could be caused by a number of things, including a loose gas cap, a faulty valve, or a leaking fuel tank. If you’d like to try to fix code P0456 at home without throwing money at parts, you’ll want to follow the steps below for proper diagnosis. Keep in mind this is an intermediate-level diagnosis and repair and not recommended for beginners. Diagnosis requires more specialized equipment beyond what the FIXD Sensor can provide and it can be a time and labor-intensive process for inexperienced DIYers.

DIY difficulty level: Intermediate

This repair requires mechanical knowledge and is not recommended for beginners.

Tools/parts needed (our top picks from Amazon):

• FIXD
• Fused power wire
• Ground wire

STEP 1: USE FIXD TO ENSURE NO OTHER ENGINE CODES ARE PRESENT.

Scan your Toyota to verify P0456 is the only code present. If other codes are present regarding fuel pressure or the fuel system, repair and diagnose those first. If it is paired with P0441, P0440, and/or P0446, there is most likely a solenoid failure, leaking charcoal canister, or a more complex EVAP leak.

STEP 2: CHECK YOUR GAS CAP.

Inspect your Toyota’s gas cap to see if it is loose or damaged. If your gas cap is loose, tighten it and clear the code. Inspect your gas cap for physical damage or deterioration. However, it should be noted that damage to the gas cap or deterioration of its components is not always noticeable. If your gas cap was not loose and you do not see any indications of failure, try replacing the gas cap anyway and clearing the codes. Gas caps are relatively inexpensive and are often the fix for code P0456.

STEP 3: CHECK HOSES.

Check for cracked or disconnected EVAP hoses near or connected to the engine air box. Replace cracked/disconnected hoses. Clear the code.

STEP 5: CHECK PURGE VOLUME CONTROL VALVE.

Check the purge volume control valve for proper operation. This valve is normally not powered on and when at rest, with no power source applied, does not allow air to pass through. It can get sticky, causing leaks. 

The purge volume control valve is usually under the hood near the airbox or intake manifold. To test, remove the hoses from either side of the purge volume control valve with the key and engine off. Blow through openings with no power supplied. If you can’t blow through them, they are sealing properly and are most likely not the cause of this medium EVAP leak.

STEP 6: CHECK CHARCOAL CANISTER VENT CONTROL VALVE.

Check the charcoal canister vent control valve for proper operation. This valve is normally not powered on and when at rest, with no power source applied, allows air to pass through. It can get sticky, causing leaks, or the internal solenoid can fail and not operate properly. 

The charcoal canister vent control valve is usually connected to the charcoal canister underneath the vehicle. To test, remove the hoses from either side of the charcoal canister vent control valve with the key and engine off, unplug it from the Toyota, and remove it from the vehicle. Blow through openings with no power supplied. Air should pass through. Now, supply a fused power source to one side and ground to the other of the electrical connector. Blow through the openings again. If you can’t blow through them, they are sealing properly and are most likely not the cause of this medium EVAP leak.

Common Toyota P0456 Diagnosis Mistakes

Many assume that a loose fuel cap is the only problem and do not perform all the tests necessary to diagnose the full EVAP system. The P0456 leak is a bit trickier to diagnose. Also, Toyota may have technical service bulletins regarding EVAP codes. Be sure to check if your particular year and model has any technical service bulletins available to save time diagnosing and/or misdiagnosing your Toyota.