Specifically, P0446 indicates an Evaporative Emission Control (EVAP) system vent control circuit malfunction. Typically, this indicates a faulty vent valve, a bad control circuit for that valve, or a blockage in the vent valve. In all cases, it clearly shows the mechanic that a check of the EVAP vent valve is in order.
carparts.com
- | What is P0446 TOYOTA code meaning? The Evaporative System (EVAP) canister vent control valve is located on the EVAP canister and is used to seal the canister vent. This solenoid valve responds to signals from the Engine Control Module (ECM).
How do I fix code P0446?
Gas caps are relatively inexpensive and are often the fix for code P0446. If the fuel cap didn’t fix it, perform an EVAP system leak check: Pinch off the vent tube to the EVAP Vent Control Valve. Pressurize the EVAP system with an EVAP smoke machine leak checker.
Where is the EVAP vent solenoid located?
In most cars, the EVAP vent valve is located underneath the vehicle, close to or at the charcoal canister near the fuel tank, see the photo.
What could cause a P0446 code?
Code P0446 is set when the car’s computer believes (either correctly or incorrectly) that there’s a problem with the vent valve. Some systems use vacuum pressure readings to judge vent valve performance. As such, in some cases, parts that might surprise you can trigger the code.
Can I drive with a P0446 code?
The P0446 code won’t put you in any immediate danger. You can still drive your vehicle if you see this code. Other than the check engine light, you may experience reduced fuel economy. While this code may not create life-threatening problems, anything that triggers a check engine light deserves attention.
What is P0446 code Toyota?
Specifically, P0446 indicates an Evaporative Emission Control (EVAP) system vent control circuit malfunction. Typically, this indicates a faulty vent valve, a bad control circuit for that valve, or a blockage in the vent valve. In all cases, it clearly shows the mechanic that a check of the EVAP vent valve is in order.
What are the symptoms of a faulty EVAP purge solenoid?
Symptoms of a Bad or Failing Canister Purge Solenoid
- Rough Idle.
- Poor Engine Performance.
- Difficulty Starting.
- Check Engine Light Comes On.
- Low Fuel Economy.
How much does it cost to replace a vent solenoid?
Replacing a canister purge solenoid is a pretty straightforward type of job that doesn’t cost too much. Expect to pay anywhere from $80 to $200 in total. The part will typically cost anywhere from $30 to $120, while the labor costs will be right around $50 to $80.
What does a vent solenoid do?
The Vent Solenoid is a normally open valve that is commanded closed to seal the EVAP system and stop air flow into the charcoal canister. The Purge Solenoid is normally closed but is opened by the PCM to allow manifold vacuum in the EVAP system — thus drawing fuel vapours from the EVAP system.
What can cause P0449 code?
Causes of Code P0449
- Missing gas cap.
- Damaged/Defective gas cap.
- Torn/Damaged EVAP system hoses.
- Faulty electrical connection.
- Damaged carbon canister.
- Damaged/Defective fuel tank.
- Defective evaporative vent valve.
What is a EVAP canister vent control valve?
The purpose of the canister vent valve, also called simply the vent valve, is to control the flow of air into and out of the Evaporative Emission Control (EVAP) system, a feature on all modern cars. The EVAP system collects and stores fuel vapors in a charcoal canister.
What does P0440 mean?
Diagnostic trouble code (DTC) P0440 stands for “ Evaporative Emission Control System Malfunction – Large Leak.” Your car’s computer (the ECM/PCM) will set the code when it determines that there’s a significant leak in the EVAP system—however, keep in mind that this doesn’t necessarily mean that there’s a leak.
Is EVAP code serious?
But because an EVAP leak can potentially be a severe and environmentally damaging problem, it’s not a good idea to keep driving with the check engine light on. Whatever condition your vehicle is in—whether it’s showing symptoms of a fuel leak or not—aim to have the codes pulled as soon as possible.
Will an EVAP code clear itself?
If the condition that caused it to come on is a minor fault, and stops occurring, then yes, it will clear itself. If the condition indicates a larger problem, then it will stay on until cleared manually.
How do you reset an EVAP sensor?
Start the engine and idle for four minutes, then drive in stop-and-go traffic for five minutes using smooth accelerations and decelerations. Stop and idle for 4 minutes. The EVAP monitor should be complete.
P0446 Evaporative Emission Control System Vent Control Circuit Malfunction
When the engine computer detects a malfunction or limitation in the vent control portion of the Evaporative emission control system, the code P0446 is set (EVAP). The description of the issue differs from manufacturer to manufacturer, but one thing is consistent: the code P0446 does not clearly indicate to a broken item; additional testing may be necessary to identify the damaged component in certain cases. Read on to learn more about how the EVAP system works. What might cause the code P0446 to appear is as follows: Faulty vent control valve -Blockage in the vent hose, filter, or vent control valve -Open or short in the vent control valve circuit -Faulty vent control valve -a faulty charcoal briquette – Leak in the EVAP system Pressure sensor failure in the EVAP system – failure of the vacuum switching valve (VSV) (Toyota, Lexus) Openpurge valve is stuck open (solenoid) Examples: – According to a General Motors technical service advisory for the 1999-2007 Chevrolet Silverado and GMC Sierra, when the vehicle is operated in a dusty environment, dust can enter the canister vent hose and create limited air flow, which can result in the code P0446 being set.
The notice suggests that the vent valve assembly be checked and, if necessary, that it be replaced with an updated part.
Repairing the EVAP vacuum switching valve (VSV) and charcoal canister as a unit is common in many Toyota cars with the code P0446, including Camry, Corolla, Avalon, RAV4, Tacoma, Tercel, as well as Lexus RX 300, ES 300, SC 400, LS 400, and LX 450 models.
In some General Motors vehicles, a faulty gasoline tank pressure sensor may also result in the code P0446.
- In most cases, replacing the purge solenoid is not particularly costly.
- It is also necessary to test the vent control valve, which is an electrical solenoid valve that closes when the electricity is delivered to the system.
- Because not every auto repair shop is equipped with this technology, you may need to take your vehicle to a dealership or a bigger, better-equipped shop for repairs.
- It is the charcoal canister that traps the gasoline vapors that escape from the fuel tank; the charcoal canister is loaded with little pellets of activated charcoal that are designed to capture and store vapors.
- The vent control valve is often located at the rear of a car or truck, either near or at the charcoal canister, to provide ventilation.
- The vent control valve is generally open, and it regulates the amount of air that is delivered to the canister.
- In order to perform the leak test, the ECM must completely shut down the EVAP system by shutting both the vent control valve and the purge control valve at the same time (solenoid).
If the EVAP system is unable to maintain the required vacuum or pressure, the ECM detects an EVAP leak.
What does this mean?
A: You may need to take your vehicle to a dealership or auto repair shop to have the problem thoroughly diagnosed.
The cost of the repair, which includes diagnostics, can range from $600 to $800.
Most of the time, however, it is the EVAP vacuum switching valve (VSV) that fails.
It has the appearance of a tiny cylindrical solenoid with a two-wire connection and vacuum lines linked to it on the outside.
Upon applying voltage to the functional VSV, it should emit an audible click and should transition between closed and open air flow modes as needed.
Q: The year is 2002.
A: The vent control valve, also known as the canister shut-off valve, malfunctions rather frequently in these vehicles.
Q: My 2005 Chevrolet Cobalt had been parked outdoors for seven months before I found it.
I took it to Autozone and had it scanned; the code was P0446.
A: If the vehicle has been parked for an extended period of time, it is not uncommon for insects to build a nest in the vent filter or vent hose, preventing the vehicle from starting.
This might result in the code. Another possibility is that the vent control valve may fail, or that a wiring or connector will get rusted.
P0446 – Evaporative Emission (EVAP) Vent Control Circuit Malfunction (Toyota) – TroubleCodes.net
| Trouble Code | Fault Location | Probable Cause |
|---|---|---|
| P0446 | Evaporative emission (EVAP) system, vent control -circuit malfunction | Wiring, EVAP canister purge valve, ECM |
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What Does Code P0446 Mean?
Fault code for the OBD II When the PCM (Powertrain Control Module) detects either a fault/defect/malfunction/failure in the EVAP vent control valve and/or its control system, or a restriction / blockage in the EVAP vent valve that inhibits the passage of atmospheric air through the valve, the code P0446 is set. When used in any application, the aim of the EVAP system is to trap and contain gasoline vapors inside the system until conditions are sufficient that the trapped vapors may be transferred to the engine and burn as part of the air/fuel combination.
- It is important to note that while the EVAP system is not in purge mode, both the vent and purge valves are closed, resulting in a complete seal between the fuel system and the atmosphere.
- When this occurs in a properly working system, the ECU opens both the purge valve and the vent valve, allowing engine vacuum to suck the collected gasses into the engine and preventing the system from overheating.
- Nonetheless, because a fully working EVAP system is a legal requirement in the majority of areas, automobile manufacturers have devised a variety of ways for detecting leaks in the system.
- The PCM can determine the size of the leak based on how quickly the vacuum decays once the purge valve is closed.
- The PCM can also determine the amount of the leak based on how quickly the pressure decreases once the pump is turned off.
- The PCM can compute the magnitude of the leak based on the change in the temperature of the vapor being emitted.
- It is also possible that the application may fail a mandatory emissions test.
- As a general rule, code P0446 can affect any vehicle; however, numerous Toyota models such as the Camry, Corolla, Avalon, RAV4, Tacoma, Tercel, as well as Lexus vehicles such as the RX 300/ES 300/SC 400/LS 400/LX 450, are particularly susceptible to this code.
To resolve code P0446 on these vehicles, the only reliable remedy is to replace both of the charcoal canisters as a unit and to remove and purge all associated hoses and vacuum lines in the EVAP system of all charcoal particles with compressed air before putting the vehicle back on the road for service.
Where is the P0446 sensor located?
The placement of the EVAP charcoal canister (circled) on a Toyota Sienna application is seen in the illustration above. It should be noted, however, that the exact placement of this component differs between impacted Toyota applications, and that you should consult the handbook for the affected application in order to accurately find and identify the charcoal canister.
What are the common causes of code P0446?
However, although disintegration of the charcoal charge in the EVAP canister is undoubtedly the most prevalent cause of code P0446 on impacted Toyota vehicles, there are numerous other probable origins of the code, which include the following:
- Damaged, burned, shorted, disconnected, or corroded wiring and or connections in the vent valve control circuit (common following a charcoal canister failure)
- Rusted wiring and or connectors in the vent valve control circuit Vent valve that is faulty (as opposed to clogged)
- Vent valve that is clogged (as opposed to defective)
- Defective EVAP pressure sensor
- Defective vacuum switching valve (common on Lexus applications)
- Vent valve that has become jammed closed due to a wiring problem
BAT Team Discussions for P0446
- Kia Sedona P0446 (2004 model year) Hello, everyone! I’m new to this site, but I was hoping to get some assistance from others. When I was traveling to town, the check engine light on my wife’s vehicle came on. I pulled over and turned it off. My car was towed to Autozone, where the mechanic diagnosed it as having the code p0446. After doing some research, I discovered that there is a TSB for this code006, as well as a 1992 Chevrolet van with a 4.2-liter V-6 that won’t start. This vehicle has a mileage of 60,000 miles. I’m receiving the error number p0446. Do you have any suggestions? 97% of the population is under the age of ninety-seven (97). Ford Explorer (Ford Explorer) Question I would start by contacting FOMOCO to determine if any programming has already been completed or if any more programming is required. Please be informed that this may not be covered under warranty. 21st of July, 1997, 97-15-22 2001
- EXPL
- MALFUNCTION INDICATOR LAMP (MIL) – MALFUNCTION INDICATOR LAMP LAMPILLUMINATED – DIAGNOSTIC TROUBLE CODES (DTCS) P0133 AND P0153 STORED IN MEMORY – EXPL
- 2002 Kia Sedona P0446 (Kia Sedona) Reply2: Today at 11:46:22 a.m. » Regarding the 2004 Kia Sedona p0446 Quote Modification – Thank you for your assistance. This code appeared around 2 months ago after driving into a snow drift. The mechanic removed the problem and it has not returned. b
- P0441 diagnostic trouble codes on a 2004 Toyota Sienna van? Toyota Sienna Van with 60k kilometers from 2004. When the vehicle is operating, three of the dashlights suddenly remain illuminated. When I phoned the dealership, they told me it was something to do with emissions. I obtained an obd-II reading, and the codes P0441, P0442, and P0446 are shown. It has something to do with the Evap Emission Control System, according to what it states. But
P0446 – Meaning, Causes, Symptoms, & Fixes
Misconfiguration of the Evaporative Emission Control System’s Vent Control Circuit
What Does P0446 Mean?
When the EVAP system is activated, fuel vapors are prevented from being released into the environment. The charcoal pellets in the charcoal canister absorb and store the gasoline vapors released by the fuel tank and stored in the fuel tank. Powered by the engine control module (ECM), the vent control valve permits air to flow into the charcoal canister, purging the gas vapors into the engine air intake where they may be burnt. The vent control valve is controlled by the ECM. A purge valve regulates the passage of gas vapors from the charcoal canister to the engine’s air intake, which allows for more efficient combustion.
Similarly, when the engine starts, the purge volume control valve closes, and the engine control module (ECM) controls its opening when it is time to purge the stored fuel vapors from the charcoal canister.
During the leak test, the ECM closes the vent control valve, resulting in an EVAP system that is completely sealed.
What Are The Symptoms Of P0446?
- When the EVAP system is activated, gasoline vapors are prevented from being released into the environment. The charcoal pellets in the charcoal canister absorb and store the gasoline vapors that escape from the fuel tank. Powered by the engine control module (ECM), the vent control valve permits air to flow into the charcoal canister, purging the gas vapors into the engine air intake, where they may be burnt. Using a purge valve, you may regulate the amount of gas vapor that is released from the charcoal canister and into the engine air intake. As soon as the engine is turned on, the vent control valve opens. Similarly, when the engine starts, the purge volume control valve closes, and the engine control module (ECM) opens it when it is time to purge the stored fuel vapors from the charcoal canister. When the vehicle is switched off, the ECM runs leak checks to confirm that the evaporative emission control system is functioning properly. In order to produce a sealed EVAP system, during the leak test the ECM closes the vent control valve. It is possible that when the P0446 code is activated, the ECM has detected a short in the circuitry used to activate the vent control valve, or that the EVAP system has failed to maintain adequate pressure during the active EVAP leak test.
What Is The Cause Of P0446?
- Gas cap that is missing, faulty, broken, or comes loose (the most frequent)
- EVAP Canister Vent Control Valve that is defective
- Fuel Tank Filler Neck that is distorted, damaged, or cracked
- Evaporative system hose(s) that have been torn or punctured
- A faulty gasket or seal on the Fuel Tank Sending Unit
- Carbon canister that is split or broken
- A gasoline tank that is defective or damaged
- Electrical connections that are open or shorted
How Serious is Code P0446? – Low
With the exception of the check engine light being illuminated, the driver is unlikely to notice any symptoms linked with P0446. However, like with other diagnostic issue codes associated with the check engine light, you should get it repaired as quickly as possible in order to restore normal functionality to the vehicle.
Tools Needed to Diagnosis Code P0496
- Fixd
- Digital multimeter
- EVAP smoke machine leak checker
- Fuses for jumping
- Vehicle-specific repair manual
How To Diagnose And Repair Code P0446:
The difficulty in diagnosing and repairing the problem is a two-out-of-five rating.
- Check to see if P0446 is the only code present on your car by scanning it. If there are any other codes present, such as those relating to fuel pressure or the fuel system, fix and diagnose those first. The most likely cause of this error code is a solenoid failure, a leaky charcoal canister, or a more sophisticated EVAP leak when it is combined with the following codes: P0441, P0440, and/or P0446. Make a visual inspection of your gas cap to see if it is loose or damaged. Tighten the gas cap if it is loose, and the error code will be cleared. Inspect your gas cap for physical damage or degradation, and replace if necessary. It should be noted, however, that damage to the gas cap or degradation of its components may not always be visible at the time of the inspection. If your gas cap was not loose and you do not detect any signs of failure, you should replace the gas cap regardless of whether or not the codes were cleared. Gas caps are extremely affordable and are frequently used to resolve the problem with code P0446. If replacing the fuel cap does not solve the problem, examine the EVAP system for leaks: Pinch off the vent tube that leads to the EVAP Vent Control Valve and set it aside. With the use of an EVAP smoke machine leak tester, pressurize the EVAP system. Check to see if any smoke is escaping out of any hoses or seals you may have installed. Whether there are any leaks, fix them and then check to see if the problem has been rectified
- If there are no leaks, check to see if the EVAP vent control valve is functioning properly. A sticky valve, dirt clogging the valve, or a malfunctioning internal solenoid can all cause this valve to stop working. To put to the test: The EVAP vent control valve should be removed from the vehicle. In most cases, the EVAP vent control valve is located under the vehicle, in the rear of it, by or attached to the charcoal canister. (Technical tip: Check to see whether you can blow through the valve’s apertures while no power or ground is connected to the system. In the event that you are unable to blow through the apertures, the valve is stuck closed and has to be repaired or replaced. Now, connect power and ground to the solenoid (consult your vehicle’s service manual to determine which pins to connect power and ground to), and the valve should click and you should no longer be able to blow through the openings. If you are able to blow through the valve while it is powered on, the valve is faulty and should be replaced. As long as the vehicle continues to generate the same code, it is possible that it has a wiring problem, and you should bring it into a shop to have additional diagnostic work done.
Estimated Cost of Repair
Make sure P0446 is the only code present by scanning your car. Other codes relating to fuel pressure or the fuel system should be repaired and diagnosed first, followed by the remainder of the codes. A solenoid failure, leaky charcoal canister, or a more sophisticated EVAP leak are all possibilities when this code is seen in conjunction with P0441, P0440, and/or P0446. Make a visual inspection of your gas cap to see whether it is loose or otherwise damaged. To clear the code, tighten the gas cap if it’s a little loose.
- The fact that the gas cap has been damaged or that the components of the gas cap have deteriorated is worth noting, though.
- When it comes to code P0446, gas caps are a low-cost solution that is frequently used; Perform an EVAP system leak check if the fuel cap didn’t cure the problem.
- Use an EVAP smoke machine leak tester to pressurize the EVAP system.
- It is necessary to fix any leaks and re-evaluate the situation to see whether the problem has been resolved; if there are no leaks, the EVAP vent control valve must be checked to ensure that it is functioning properly.
- For testing purposes, we will use the following information: Exhaust gas aftertreatment system (EVAP vent control valve) removal In most cases, the EVAP vent control valve is positioned under the vehicle, in the back of it, near or linked to the charcoal canister.
- (If you are unable to blow through the apertures, this indicates that the valve is jammed closed and has to be repaired.) Provide power and ground to the solenoid (see your vehicle’s service manual to determine which pins to use for power and ground).
- If you are able to blow through the valve when it is switched on, the valve is malfunctioning and has to be replaced.
- Gas Caps range from $20 to $60
- EVAP Lines range from $20 to $100
- And EVAP Vent Control Valve range from $150 to $200.
P0446 Toyota EVAP vent solenoid
Toyota is experiencing a significant number of breakdowns in their exhaust gas recirculation systems. The vent solenoid is the source of the most prevalent error code, P0446. During a purge cycle, this is the solenoid that opens in order to enable air to enter the charcoal canister. Normally, the solenoid is in the closed position. This device opens and enables air to enter when powered. If it remains open, the pressure sensor on the charcoal canister will not detect a rise in vacuum, resulting in the occurrence of code P0446 on the computer.
- Located on the air intake, the canister closed valve keeps the canister closed.
- If the valve is generally closed, it should be capable of maintaining vacuum.
- After that, turn off the electricity and turn on the vacuum again.
- If the solenoids are not functioning correctly, they should be replaced with new ones from Toyota.
- Rick Muscoplat posted a blog entry on
P0446 Code: EVAP Circuit Issue (Symptoms, Causes, and How to Fix)
The most recent update was made on October 6, 2021. All automobiles are equipped with an evaporative emission control (EVAP) system, which is especially intended to prevent the release of pollutants into the environment. When you reinstall your gas cap, it seals the tank, trapping the fuel and its contaminants inside. Are you looking for a reliable online repair manual? The top five choices may be found by clicking here. Fuel vapors pass via a vent line and into a charcoal canister, where activated charcoal absorbs some of the fumes and releases them into the atmosphere.
The purge valve is responsible for transporting vapors to the engine air intake.
If the vent control valve does not function properly, the P0446 error code is shown.
What Does Code P0446 Mean?
P0446 is an OBD-II trouble code that has a description. System for Controlling Evaporative Emissions Malfunction of the Vent Control Circuit The vent control valve and the purge valve are responsible for the operation of the EVAP system. In order to keep the system running, the vent control valve draws fumes into the system and pushes them out through the purge valve. The purge valve serves as an outlet for air entering the engine’s intake system. The only way for fumes to get through the purge valve is if the ECM instructs the vent control valve to allow air to pass through.
These problems are discovered during the ECM’s routine testing.
Closing the valve entirely shuts down the EVAP system, and no air or fumes should be allowed to escape.
When the vent control valve is unable to maintain sufficient pressure to close the EVAP system, the P0446 error code is generated. Take a look at these more resources: P0456 (EVAP System – Small Leak Detected) is a diagnostic code.
Symptoms of Code P0446
Description of OBD-II Trouble Code P0446 A system for reducing evaporative emissions a malfunction in the vent control circuit The vent control valve and the purge valve are responsible for the proper operation of the EVAP system, respectively. Because it draws in gasses and then expels them through the purge valve, the vent control valve helps to keep the system running smoothly. When the engine is not running, the purge valve serves as the engine’s air intake’s departure valve. The only way for fumes to get through the purge valve is if the ECM instructs the vent control valve to allow air to flow through it.
It is discovered that these problems exist during routine testing of the ECM.
Closed EVAP valves ensure that no air or fumes may escape from the vehicle once it has been shut off.
Check out these other resources as well.
Causes of Code P0446
P0446 is an OBD-II trouble code with a description. System for Evaporative Emission Control Failure of the Vent Control Circuit The vent control valve and the purge valve are responsible for the proper operation of the EVAP system. In order to keep the system running, the vent control valve draws fumes into the system and then expels them through the purge valve. The purge valve serves as an outlet from the engine’s air intake system. The only way for fumes to get through the purge valve is if the ECM instructs the vent control valve to open.
These flaws are discovered during the ECM’s routine testing.
Closing the valve totally shuts down the EVAP system, ensuring that no air or gases escape.
Take a look at these other resources: A small leak was detected in the exhaust ventilation system, resulting in code P0456 (EVAP system – small leak detected).
- Vent control valve:If your vent control valve isn’t operating properly, two things might happen. It is possible that a malfunctioning vent control valve may lock the fumes within with nothing to move them, or that the vent control valve will be unable to maintain sufficient pressure to keep the vapors sealed in at all. Fuel tank filler neck: If there is a fracture in the fuel tank filler neck, pressure will not be able to hold. The crack will cause the pressure from the vent control valve to become unstable. It is also possible to deform or damage the gasoline tank filler neck in another method in order to achieve the same result. Hoses for the EVAP system: It is also possible for pressure to escape from the EVAP system’s hoses. A smoke test can be used to diagnose this problem. Gasket or seal for the fuel sending unit: This gasket or seal guarantees that the fuel remains contained within the unit and does not leak out into other areas of the car. Even if there is no leakage of fuel, the pressure may be reduced. The canister containing the charcoal may break or get damaged. The charcoal canister is critical to the EVAP system since it is the primary component that retains fumes. Fuel tank: Because the fuel tank supplies the EVAP system with fuel, the P0446 error number may be shown on the computer screen. Electrical connections: Vehicles, like computers, rely on electrical connections to operate. The EVAP system is adversely affected by a shorted or open electrical connection.
Is Code P0446 Serious?
You are not in any imminent risk as a result of the P0446 error code. If you see this code, you can continue to use your car. In addition to the illuminated check engine light, you may notice decreased fuel economy. Even though this code does not appear to cause any life-threatening issues, anything that causes the check engine light to illuminate ought to be investigated.
How to Fix
In order to resolve the code P0446, you must first examine the gas cap. EVAP system problems can be caused by a variety of factors, making them more difficult to detect. The most efficient strategy is to take a gradual approach, starting with the least severe and progressing to the most severe. If the gas cap is broken, damaged, or decaying, it should be replaced before the code may be cleared. If the P0446 error code continues to appear, look for a leak. Some mechanics do a smoke test to look for leaks in their vehicles.
After you have repaired any holes that you may have discovered, you should clear the code.
It is possible that they are sticky, blocked, or that they have an internal solenoid failure.
Try blowing through the vent control valve to see if it helps. If it won’t open, it’s possible that it’s stuck or clogged. Replace any broken components with new ones, clean the pieces that are already in place, and check for the P0446 error code once again.
Toyota Corolla P0446: EVAP Vent Control Circuit – Malfunction
The P0446 fault code is one of the most often seen when driving a Toyota Corolla. When you insert your Corolla into an OBDII scanner, you will be issued a fault code that corresponds to the number you are given. The code P0446 indicates that there is a problem with the evaporative emission control system. It is frequently used in conjunction with other codes, such as P0420, P0441, or P0440. Misconfiguration of the evaporative emission control system’s vent control circuit (P0446). P0446 is usually not a serious danger to your vehicle’s ability to drive in the short term.
It is frequently seen in conjunction with P0442.
Toyota Corolla P0446 OBDII Code Symptoms
The check engine light will most likely be the sole symptom of P0446 in the majority of cases. In most cases, the P0446 error number will not be accompanied by any obvious symptoms. The service engine soon light will illuminate, but that is generally the extent of the problem. It is possible (though not very likely) that you will notice a modest decline in fuel economy. P0446 may potentially cause a small gas smell to emanate from the computer. This is owing to the fact that it has something to do with the system that deals with gasoline vapors.
Toyota Corolla P0446 Meaning
P0446 is an OBDII error code that might be encountered anywhere. This implies that no matter what make or model of car is involved, the code will always indicate the same thing (Corolla or not). Technically, the code is comprised of the following letters: Misconfiguration of the Evaporative Emission Control System’s Vent Control Circuit When the EVAP system is activated, it catches all of the fuel vapor from the tank and directs it to the engine’s intake, where it may be burned as part of the usual combustion process.
Corolla P0446 Trouble Code Causes
P0446 fault code in your Toyota Corolla can be triggered by a variety of different events or circumstances. The following are the most typical issues that may result in the code being thrown:
- Vapor Canister Purge Valve – The vapor canister purge valve is one of the most prevalent reasons of the P0446 error number. It is really simple to replace. There are a couple of clips that you’ll need to locate and unclip
- EVAP System Line – The hose that transports the fuel vapor from the fuel tank to the intake manifold might develop a leak at some point. This will result in the P0446 error code. Observe the item for signs of wear or a rip or a hole
- P0446 is frequently caused by a faulty charcoal canister
- However, this is not always the case. When the fuel tank sending unit fails, it is conceivable that the fuel tank may not fill with fuel. This can cause problems with line pressure and cause the code to malfunction. Fuel Cap – A faulty fuel cap will very certainly result in the code being thrown. Occasionally, you’ll receive a notification notifying you that the fuel cap is not in place, even when it is. Whether you are seeing that warning in addition to a P0446, it may save you a great deal of time and money to just replace the fuel cap and see if the problem is resolved. Gasoline Filler Neck – Where the fuel filler neck joins to the gas tank, a gasket is frequently used to seal the connection. This gasket is susceptible to drying out, particularly in automobiles that spend a significant amount of time in arid areas. When it dries out, the fuel tank is no longer able to maintain pressure
P0446 Diagnosis- Toyota Corolla
Purge Valve for the Vapor Canister – The vapor canister purge valve is one of the most prevalent causes of the P0446 code. Replaceing it is a simple procedure. Identify and remove a couple of clips that you’ll need to get rid of. EVAP System Line – The hose that transports the fuel vapor from the fuel tank to the intake manifold might develop a leak at any point. The P0446 error code will be generated as a result of this. Observe the item for signs of wear or a hole; P0446 is frequently caused by a faulty charcoal canister; however, it can also be caused by other factors.
Because of this, line pressure might become erratic, resulting in code errors.
When the gasoline cap is off, you’ll frequently receive a notification telling you that the engine is running.
This will save you a lot of time and money in the long run.
Especially in automobiles that spend a significant amount of time in dry regions, this gasket can become brittle and fail. As a result, the gasoline tank loses its ability to maintain pressure.
- In most cases, the mechanic will check to see if there are any additional fault codes present. The greater the number of issue codes available, the easier it may be to detect a problem. This is due to the fact that when they occur together in specific combinations, there will frequently only be a few situations that will cause any combination of codes to be thrown at the same time
- In most cases, after determining which fault codes are associated with the P0446, the technician will proceed to examine the EVAP system. The purge valve, line, and canister are all included in this. The mechanic will examine the gas cap to ensure that it is capable of withstanding the pressure. In the event that you are receiving a warning that your gas cap is off, even while it is turned on, replacing it will almost certainly remove the code. There will be an inspection and monitoring of the gasoline tank pressure. Following the completion of the above-mentioned examinations and repairs, the mechanic will conduct two tests: EVAP solenoids and valves will be tested using a smoke test, and a scan tool will be used to ensure that they are performing properly.
Most Common P0446 Fixes
The following are the most often encountered Corolla P0446 issues:
- Replacement of the gas cap
- Replacement of the EVAP line
- Replacement of the charcoal canister
- Replacement of the fuel tank
Replacing the gas cap, the EVAP line, the charcoal canister, and the fuel tank are all necessary.
Getting code p0446
- Date of joining: February 8, 2017 Member:210037 Messages:738 Gender:Male Ryan’s given name is Ponce Inlet, Florida. Vehicle:2004 Toyota Tacoma 3.4L Double Cab TRD3′ ome lift 883. Fnfx professionals’ Today is the first time I’ve seen it. I went to Auto Zone and had the code examined there. The only code that appears is p0446. It specifies that the charcoal canister should be replaced. Has anyone have any previous experience with this? I looked at some web videos, however it appears that my 2004 Toyota Tacoma looks different under the hood than the 2002s in the movies I saw. Even the location of the charcoal canister is a mystery to me at this point. The most recent revision was made on January 26, 2020.
KleenaxWell-Known Member
- Date of joining:Mar 24, 2017 Member:214267 Messages:415 Gender:Male RayMichigan’s given name is RayMichigan. CBI bolt-on Sliders
- New framestuff
- 2001 SR5 4WD V6 Automatic in Mica Green
Black DOG LilaWell-Known Member
- Date of joining:June 14, 2019 Member:296344 Messages:8,298 Virginia Vehicle:2003 Toyota Tacoma SR5 2.7 5-speed 4WD with a 2.7-liter engine. Stock up on EZ passes. Dump pass is what you need. Sticker for inspection. Convicts printed their own license plates. Cap for the FG
Black DOG LilaWell-Known Member
- Date of joining:June 14, 2019 Member:296344 Messages:8,298 Virginia SR5 2.7 5 speed 4WD Toyota Tacoma (2003 model) Stock up on EZ passes. Dump pass is what you need. Sticker for inspection. License plates with the insignia of a convict. Also, replace your brake fluid because it’s dirty as hell. The canister is located underneath the truck, generally near the gasoline tank. The likelihood of it becoming contaminated is limited, unless you overfill the tank or have experienced a serious fuel system problem. First and foremost, inspect the lines and vac plugs. Everything is in order, so start with the cheapest element first. It’s on top of your petrol tank, just next to the charcoal canister. It is not the simplest thing to replace. The bed will have to be dismantled, and the tank will have to be dropped. It’s less difficult to remove the bed, at least according to what I recall from previous articles. It’s possible that your charcoal canister isn’t the problem. First and first, rule out anything.
SellyKlaterWell-Known Member
- Date of joining: February 8, 2017 Member:210037 Messages:738 Gender:Male Ryan’s given name is Ponce Inlet, Florida. Vehicle:2004 Toyota Tacoma 3.4L Double Cab TRD3′ ome lift 883. Fnfx professionals’ Is there a way to find out for certain? With the use of some sort of test
cruiserguyWell-Known Member
- 8th of February, 2017 was the date of joining. Member:210037 Messages:738 Gender:Male RonPonce Inlet, Florida (first name): 2004 Toyota Tacoma 3.4L Double Cab TRD3′ ome lift 883. Fnfx professionals’ Is there a way to be certain? Some sort of examination
cruiserguyWell-Known Member
- Date of joining: July 31, 2016 Member:193416 Messages:19,069 Gender:Male ElijahSLCV is his given name. Vehicle: 2000 extended cab, 2.7L, automatic, 4×4 cab. Please, hold on a sec. P0446 does not state that the charcoal canister should be replaced. This is what it says: Exception P0446: Vent Control Circuit Malfunction in the Evaporative Emission Control System When the engine computer detects a malfunction or limitation in the vent control portion of the Evaporative emission control system, the code P0446 is set.
SellyKlaterWell-Known Member
- Date of joining: February 8, 2017 Member:210037 Messages:738 Gender:Male Ryan’s given name is Ponce Inlet, Florida. Vehicle:2004 Toyota Tacoma 3.4L Double Cab TRD3′ ome lift 883. Fnfx professionals’ That’s exactly what the auto zones computer said when the code was entered
SellyKlaterWell-Known Member
- Date of joining: February 8, 2017 Member:210037 Messages:738 Gender:Male Ryan is his given name. Ponce Inlet, Florida is a town in the state of Florida. Vehicle:2004 Toyota Tacoma 3.4L Double Cab TRD3′ ome lift 883. Fnfx professionals’ I have some stainless steel brake lines that I’ve been wanting to install. Haha. Make sure you have fresh brake fluid on hand. I swear to you, haha. The most recent revision was made on January 26, 2020. It’s never that straightforward. Not a single one of the codes says, ‘This is the one!’ The OP should conduct some research and eliminate as many possibilities as possible. The link I provided, which the OP even admits striving to rule out, but in his instance, it was determined that the charcoal canister was the culprit. Link once again ()
cruiserguyWell-Known Member
- Date of joining: July 31, 2016 Member:193416 Messages:19,069 Gender:Male ElijahSLCV is his given name. The vehicle is a 2000 ext cab with a 2.7L engine, automatic transmission, and 4×4.
Black DOG LilaWell-Known Member
- Date of joining:June 14, 2019 Member:296344 Messages:8,298 Virginia SR5 2.7 5 speed 4WD Toyota Tacoma (2003 model) Stock up on EZ passes. Dump pass is what you need. Sticker for inspection. License plates with the insignia of a convict. The purging selnoid may be tested using a 9volt battery, however in actual service, it is more likely to function occasionally. It’s a $36 component available on Amazon. EVAP codes are frequently generated by the gas cap seal and filler neck sealing surface, respectively.
cruiserguyWell-Known Member
- June 14, 2019 – Become a member! Member:296344 Messages:8,298 Virginia SR5 2.7 5 speed 4WD Toyota Tacoma (2003 model). Quick pass. Stock up on essentials like this. Pass the dump. Sticker for the inspection. License plates with the insignia of the convict. It is possible to test the purge selnoid using a 9volt battery
- Nevertheless, this device frequently fails sporadically in real-world situations. According to Amazon, it costs $36. It is usual for EVAP codes to be generated by the gas cap seal and filler neck sealing surface2.
cruiserguyWell-Known Member
- Date of joining: July 31, 2016 Member:193416 Messages:19,069 Gender:Male ElijahSLCV is his given name. Vehicle: 2000 extended cab, 2.7L, automatic, 4×4 cab. Is it possible for the purge valve to generate loud noises, such as very LOUD click type noises
cruiserguyWell-Known Member
- Date of joining: July 31, 2016 Member:193416 Messages:19,069 Gender:Male ElijahSLCV is his given name. The vehicle is a 2000 ext cab with a 2.7L engine, automatic transmission, and 4×4.
Black DOG LilaWell-Known Member
- When: July 31, 2016 when you first joined Member:193416 Messages:19,069 Gender:Male Name:ElijahSLCV First and middle names: Vehicle: 2000 extended cab, 2.7L, automatic, 4×4 (with a tow package).
Black DOG LilaWell-Known Member
- Date of joining:June 14, 2019 Member:296344 Messages:8,298 Virginia SR5 2.7 5 speed 4WD Toyota Tacoma (2003 model) Stock up on EZ passes. Dump pass is what you need. Sticker for inspection. License plates with the insignia of a convict. They just want to make the most money possible by selling you the most costly parts. Preying on people’s fears as a result of the dreaded check engine light
SellyKlaterWell-Known Member
- Date of joining: February 8, 2017 Member:210037 Messages:738 Gender:Male Ryan’s given name is Ponce Inlet, Florida. Vehicle:2004 Toyota Tacoma 3.4L Double Cab TRD3′ ome lift 883. Fnfx professionals’ Toyota Part Number: 25860-75230 The Vapor Canister Purge Solenoid costs $83 dollars. It appears to be about correct
Toyota Camry Fault Code P0446 Evaporate Control System
In this case, the P0446 fault code indicates an issue with the EVAP Vent Control Circuit, which is particular to the EVAP system in question. It’s possible that your Toyota Camry’s EVAP vent valve is stuck open, unclean (producing high resistance), or shorted due to a number of factors. In order to keep the EVAP canister sealed, the vent valve is utilized. When you fix (replace) the EVAP vent valve, you are more than likely to receive the fault code P0446. Vent valve is a component of the Toyota Camry EVAP Charcoal Canister, which means that it must be changed as a single unit.
When the key is turned on, the vent valve is typically supplied with Batt.
The driver of the ECM is in charge of controlling the ground, and when grounded, it activates the valve (closing it).
It is also possible to set P0446 if the ECM detects that the EVAP system is unable to establish or maintain vacuum throughout the testing process.
P0446 Diagnostics: Hello Everyone, I Failed a Smog Check Due to .
In this case, the P0446 fault code indicates an issue with the EVAP Vent Control Circuit, which is unique to the EVAP system in question. In some cases, the EVAP vent valve on your Toyota Camry may be jammed open, unclean (resulting in heightened resistance), or shorted out. In order to keep the EVAP canister sealed, the vent valve is utilized. Repairing (replacing) the EVAP vent valve will almost certainly result in a fault code P0446 being displayed on the dashboard. When replacing the Toyota Camry EVAP Charcoal Canister, the vent valve must be replaced as a single piece.
This allows the ECM to pressurize the EVAP system and guarantee that there are no leaks.
The ground is controlled by the ECM’s driver, and when the ground is grounded, the valve opens (closing it).
It is also possible to set P0446 if the ECM determines that the EVAP system is unable to create or maintain vacuum throughout the testing process.
Toyota DTC P0446
Some professionals are living proof of the old adage that a little bit of knowledge can be a hazardous thing. He or she tries to transform one piece of information—for example, a DTC description—into a complete and accurate evaluation. This has happened to me multiple times with the DTC P0446 on Toyota vehicles, in particular. The following suggestions may assist you in resolving this error code more quickly and efficiently. The testing of Toyota’s evaporative emissions systems is a massive undertaking.
- However, I felt it was past time to examine its ‘intrusive’ system, as well as two of its actuators: the canister closure valve (CCV) and the bypass solenoid valve (BSV).
- They are both solenoid-operated valves, as is the case with the other evap actuator.
- In any case, the CCV and the bypass valve share a number of important characteristics in common.
- Second, the solenoids that control the CCV and the bypass valve are either completely on or totally off electrically; they are not pulsed.
- As a result, the CCV and bypass valve are electrically disabled for the majority of the time.
- For example, the CCV is mechanically open in the usual direction.
- As a result, the CCV acts as the primary back door for the entire invasive evap system.
In terms of automobile and engine combination, the 4-cylinder Camry is Toyota’s most popular model.
It’s important to search all around and below the air cleaner housing if you don’t see a CCV placed directly on the air cleaner housing.
The bypass valve, on the other hand, is generally closed mechanically rather than being open, as would be expected.
(In the photo on page 14, you can see a new bypass valve that I had just put on a Toyota Camry.) Naturally, the bypass valve is exposed to the worst of the elements because it is located in this area.
Furthermore, when it comes time to replace your old one, you may discover something unusual: It is possible that the sheet-metal casing that surrounds the bypass valve has corroded away in part or whole!
Toyota utilizes a fuel tank pressure sensor known as the vapor pressure sensor to monitor fuel tank pressure (VPS).
By doing so, the bypass valve is manually opened, allowing the VPS sensor to detect the pressure of the whole evaporative cooling system.
The first and most important reason is that these two components will automatically identify the system for you.
Second, one of these components might fail, resulting in a P0446 code being shown on a Toyota invasive evap system.
That should be confirmed by a few straightforward experiments.
This might be due to the fact that the CCV is so easily accessible.
You may run a variety of tests on the entire invasive system to see how effective it is.
First and foremost, be certain that you have a contemporary scan tool that is capable of working with Toyota automobiles.
The bypass solenoid valve and the VPS sensor, on the other hand, are buried beneath the back of the car, which is a pain!
(A scan instrument can only energize one of these evap solenoids at a time while using this technique.) Consider the following scenario: you are attempting to ignite either the CCV or the bypass solenoid using your scan tool.
The bypass valve’s characteristic sound is sometimes more of a thud than a click, depending on the situation.
When in doubt, I remove the scan tool from the car and position myself as close as possible to the CCV or bypass valve so that it is easy to hear it operating properly.
Typically, a CCV or bypass valve is considered to be in excellent working order if it quickly clicks on command.
Place your index and middle fingers on the CCV or bypass valve.
The majority of the time, you can feel and hear these components click when they are instructed to do so.
Occasionally, the bypass valve will not reply to a single order, so test multiple successive commands to determine whether it will respond consistently.
Remove the CCV from the air cleaner housing and detach the hose that connects it to the canister, for example.
Then, using your smoke machine, force smoke through the CCV until it is completely filled.
It should be easy to pass smoke through the CCV until you re-energize it with the scan tool.
Otherwise, it is either jammed open or is leaking fluid.
A decent CCV should be able to maintain vacuum until the scan tool is used to electrically shut it off.
It is not difficult to verify if the bypass valve is operating mechanically.
Typically, the VPS signal is shown by a scan equipment in millimeters of mercury.
A signal less than or equal to 762mm-Hg indicates a negative pressure or vacuum; a signal larger than or equal to 762mm-Hg indicates a positive pressure or atmosphere.
One hose connects the purge valve to a vacuum port on the intake manifold, while the other connects the purge valve to the canister side of the evap system (see illustration).
When you restart the engine, the manifold vacuum will be applied to the canister side of the system, which is a good thing.
Close the rear end of the invasive system by gently clamping off the CCV hose with a pinch-off tool that is suited for the job.
To activate thebypasssolenoid valve, you’ll need your scan tool just a second or two more.
If the VPS reading declines after you start the engine, it is likely that the bypass valve has failed.
In that situation, the bypass solenoid should be activated.
Pay close attention to the following: When the VPS signal reaches around 735 to 740mm-Hg, the bypass solenoid should be turned off.
The fact that it is constant indicates that there are no leaks on the fuel tank side of the system—including at the bypass valve—and that the system is operating properly.
It is common for the VPS signal to climb rapidly when there is a leak on the fuel tank side. Hopefully, these instructions will save you both time and aggravation. Keep your smile on, and I’ll see you again next month.
Toyota Sienna Evaporative Canister (P0446) and SVS Valve Repair or Think Like a Maker
Update: The process outlined below was successful in resolving the issue, and the repaired SVS valve lasted almost 18 months until the car began to display the same error number. In 2012, I changed the SVS valve with the replacement described below, and the car has not thrown any errors in the intervening two years. If you have a vehicle other than a Sienna, go to Amazon and seek for valves that are labeled ‘Dorman 911 vacuum valve’ or something similar. – JakeRage picked me up and drove me there.
The fault was with the evaporative emissions control system (codeP0446), and so I brought it into the dealership to be repaired.
Since then, a number of events have transpired.
Nothing can withstand the heat of the hot wrench (mechanic’s terminology for an oxy/acetylene cutting torch), even the most rusty nut or bolt.
Consequently, when the dealer contacted and offered me a quotation of $720, my answer was ‘Seven hundred and twenty dollars to repair a part that is basically a paint can full of charcoal!
As a result, I purchased a code reader from Scantool and conducted some research on frequent failure modes.
The charcoal canister for evaporative emissions in my 2001 Toyota Sienna is placed behind the plastic shield between the gas tank and the spare tire, on the driver’s side.
There was no liquid gasoline in the system, and just a faint scent of gas emanated from the canister, indicating that it had not been completely soaked.
I decided to pressure test the charcoal canister because it was identified as one of the probable failures that may result in the ODB-II code P0446 by the scan tool.
Although Toyota has bonded the snap-tabs in place, the bastards have prevented me from disassembling and inspecting the insides of these vacuum valves to ensure that they were functioning properly.
This is the SVS Valve, and it is supposed to be closed until the circuit is activated; however, mine was stuck open during the test.
It was impossible for me to travel back to the dealer for a replacement component, so I decided to try if I could fix it myself.
The silver plunger on the right was, in fact, jammed up against the inside of the barrel.
The next step was to insert a piece of thin-walled brass tubing that was slightly bigger than the bore into the hole created previously.
I had a sneaking suspicion that the plastic in the valve body had expanded a teeny-tiny little as a result of years of exposure to gasoline fumes.
Everything was put back in the car, and I used the scan tool to remove the P0446 error number from the computer.
I did have to pay $98.95 for the scantool, but it was necessary since it was time to start working on my own vehicles again, and they were all ODB-II, so I needed one anyhow, and it was still far cheaper than the $720 the dealer charged.