P2418 - OBD Trouble Code

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An EVAP leak is a fault in the evaporative emission control system (EVAP). The EVAP’s function is to keep gasoline fumes in the fuel tank from reaching the atmosphere. This keeps air pollution down and keeps the smell of fuel from reaching the inside of your vehicle. Fuel vapors are emitted from vehicles any time there is gasoline in the tank. So if you have a leak, even if you are not driving the vehicle, those vapors are polluting the air 24 hours a day. Uncontrolled emissions like this account for about 20 percent of the pollution produced by vehicles.

The switching valves plays a vital role in preventing these fumes from escaping and thus, if there’s any problem with the control circuit, OBD code P2418 can get stored in the PCM.

The charcoal canister contains charcoal which absorbs and stores the fuel vapours. When the time comes to “purge” the vapours, fresh air passes over the charcoal and this releases the vapours. When engine operating conditions are correct, the purge solenoid opens the purge valve. This allows fuel vapours to be sucked into the engine and burned.

Enhanced EVAP systems use a canister vent solenoid and valve during system self-testing. The PCM closes the valve, sealing the canister off from outside air. Then, the PCM can monitor the closed system and check it for leaks. Once the engine is shut down, the powertrain control module (PCM) tests the integrity of the EVAP system. It does this by closing off the system and monitoring pressure/vacuum to check for leaks. Code P2418 indicates the PCM has detected an open or short in the control circuit of the EVAP switching valve.

What causes this problem with the Evaporative Emission System Switching Valve Control Circuit/Open?

• EVAP switch valve or control solenoid faulty
• Loose fuel filler cap
• Damaged purge control solenoid
• Charcoal canister clogged or damaged
• Vacuum leak or damaged hoses
• Faulty fuel pressure or flow sensor

1. Engine Control Module - Most of the time it is difficult to intercept the ECM faults and thus must be checked for thoroughly. There can be a problem with the circuit or the software might have malfunctioned. Thus repair, replace or reprogram the component as per requirement.
2. Powertrain Control Module - If the PCM is faulty, it can stores wrong OBD codes and can lead to misdiagnosis. This can happen due to misinterpretation of data received from the various sensors and components which also affects the vehicle’s performance. Thus replace it immediately.
3. Electronic Control Unit – If the ECU is at fault, it will not be able to read the boost converter temperatures correctly leading to underperformance. Thus, replace faulty ECU now!
4. Diagnostic Tool - Choose from our diagnostic tools collection that will come handy to detect and correct the OBD error code.
5. Fuel Cap - If you get an error pointing to the gas cap it means fuel vapors are leaking out of your cap. This means the cap is either cracked or just wasn’t tightened well enough. Thus, replace it now!
6. Fuel Tank Pressure Sensor - Also known as the fuel rail sensor, the fuel tank pressure sensor is an integral part of the evaporative emissions control systems or rather EVAP. The EVAP captures unburned fuel vapors from the fuel tank and reintroduces them into the fuel system. It helps in many ways, most importantly by saving fuel, minimizing environmental pollution, and preventing damage to the engine. The pressure sensor, which is normally positioned inside or on top of the tank, works to detect the pressure in the fuel system, with the end goal of identifying leaks and defective gas caps.
7. EVAP Leak Detection Pump - Basically a leak in the EVAP system will make the LDP keep pumping, since there is an escape for the air pressure. It is precisely the job of the LDP to detect such leaks. A vacuum problem to the upper chamber will render the LDP inoperative. The atmospheric line can actually be broken without affecting the system. In this case, the LDP will suck air through it instead of the LDP air filter.
8. Vapor Canister Valve - If your canister purge valve is stuck open, however, it creates a vacuum leak that can affect your engine adversely. Simply put, air will be allowed to enter the engine in a quantity that is not predicted by your car’s computer. This will change the car’s air to fuel ratio, and can cause rough idling (car feels rough and bouncy when the engine is running), as well as difficulty starting. If experienced in tandem, there is a high likelihood of a failing canister valve, or some other part of the EVAP system.
9. Vapor Canister Purge Solenoid - A defective canister purge solenoid may also set off the Check Engine Light. If the computer detects any problem with the purge solenoid circuit or signal, it will set off the Check Engine Light to alert the driver that a problem has occurred. A Check Engine Light can also be caused by a wide variety of other problems, so it is recommended to have the vehicle scanned for trouble codes to be sure.

Have you ever wondered why it is so important to know the symptoms of the problem? Well, it is extremely essential to know the symptoms of the problem in order to detect it. Keeping this in mind, let’s throw some light on few common symptoms of OBD error code P2418.

Common Symptoms

• Affected fuel economy
• Increased exhaust emissions
• Check engine light ON
• Rough engine idles
• In rare cases, complete engine failure

To correct this issue, you might need to undergo few replacements for the defective parts such as:

• Faulty wiring repair or replacement
• EVAP pressure sensor repair or replacement
• Fuel cap replacement
• Faulty EVAP valves replacement
• EVAP pump circuit and connections corrections
• Purge solenoid replacement

If you need any parts to fix this problem you can easily find them with us. Not only that we also have in stock the best in range auto parts and that too at the most budget friendly prices ever online. Whether you need a Switching Valve, Pcm, Fuel Vapor Hoses, Fuel Pressure, Flow Sensor, you can simply rely on us for quality auto parts.

Here are some steps which you should follow in order to diagnose this fault code P2418:

Scan codes and document the code in the PCM, view the freeze frame data to see when fault happened. Inspect the entire vapour purge valve system to include the purge valve and vent valve hose connectors for damaged or loose connections

Check the purge valve vent for any blockage from dirt, debris or spider webs that could cause the valve to not be able to complete a total seal of the vapours. Perform a smoke leakage test on the fuel vapour system to try and locate the cause of the vapour leak using the test vapour port, checks the fuel cap for vent leakage

Inspect the EVAP pump for any problems in association to the circuit wiring and connectors and resolve them immediately.

Check the purge control valve to see if it will hold a vacuum when activated. Also check for faults in the PCM and repair or reprogram as required.

Common Mistakes When Diagnosing The P2418 Code

Not checking and assuming the EVAP pump is defective without doing a thorough diagnostics of the complete system to later find the wiring is broken or cut, not verifying the leak and replacing parts that may or may not be the problem, and not checking for any technical service bulletins that may have a fix for the code are some of the common mistakes.