P2402 code — how to fix error fast

Facing the code P2402 is surely something you’d want to avoid, but it’s one of the most common OBD2 error codes, so it’s no wonder many drivers experienced it. If this happens to you, the best piece of advice you can get is to stay calm and make your way to the solution as fast as possible.

To help you with that, and also with an understanding of the P2402 code meaning, our team has put all the essential pieces of information about the code into this one guide. So, make sure you stay until the end as we’ll start with the meaning behind the code and its main causes, and go through the fixes before we wrap things up with preventive measures.

Why you can trust REREV’s OBD2 code advice: Our automotive expert researchers with experienced mechanics undertakes a thorough research methodology to deliver precise insights on OBD codes. Find out more about OBD2 codes research process..

What does the P2402 code mean?

The P2402 code is a diagnostic trouble code (DTC) that indicates a problem with the evaporative emission system. This system is responsible for capturing and storing fuel vapors that would otherwise be released into the atmosphere. When this system detects a leak, it can trigger the P2402 code.

It’s important to understand the P2402 code because it can have a significant impact on the performance of your vehicle. If left unaddressed, it can lead to decreased fuel efficiency and increased emissions. Additionally, some states require vehicles to pass emissions tests in order to be registered, and a P2402 code can cause a vehicle to fail these tests.

What causes the P2402 code?

There are several potential causes of the P2402 code. One common cause is a loose or damaged gas cap, which can allow fuel vapors to escape from the fuel tank. Still, it’s important to stay updated on all the possible reasons behind the code, so here’s a complete overview:

Faulty EVAP system pressure sensor

The EVAP system pressure sensor is responsible for measuring the pressure in the fuel tank and sending this information to the engine control module (ECM). If this sensor is faulty, it may send an incorrect signal to the ECM, triggering a P2402 code.

Leaking or damaged EVAP hoses

The EVAP system hoses are responsible for carrying fuel vapors from the fuel tank to the engine. If these hoses are leaking or damaged, they may allow fuel vapors to escape into the atmosphere, triggering a P2402 code.

Faulty fuel cap

The fuel cap is responsible for sealing the fuel tank and preventing fuel vapors from escaping into the atmosphere. If the fuel cap is faulty or not tightened properly, it may allow fuel vapors to escape, triggering a P2402 code.

Faulty purge valve

The purge valve is responsible for regulating the flow of fuel vapors from the EVAP system to the engine. If this valve is faulty, it may cause a leak in the system, triggering a P2402 code.

Which car models does the P2402 code affect the most?

While the P2402 code can potentially affect any vehicle with an evaporative emission system, there are certain car models that may be more prone to this issue. Some of the models that have been known to experience problems with the P2402 code include:

• Audi A4: Some models of the A4, particularly those manufactured between 2010 and 2013, are known to be more prone to EVAP system issues than others.
• BMW 3 Series: Also, models of the 3-Series, particularly those manufactured between 2006 and 2011, are known to be more prone to EVAP system issues than others.
• Ford F-150: The F-150 models, particularly those manufactured between 2009 and 2013, are known to be more prone to EVAP system issues than others.
• Honda Civic: The Honda Civic is a compact car that has been in production since 1972. Some models of the Civic, particularly those manufactured between 2006 and 2011, are known to be more prone to EVAP system issues than others.

How to diagnose the P2402 code

Once you have identified the cause of the P2402 code, you will need to take steps to fix the issue. Depending on the specific cause of the problem, this may involve replacing a damaged component, tightening a loose connection, or repairing a leak in the system, so let’s have a look at the various ways of diagnosing the code:

Use an OBD2 scanner

You can connect a scan tool to the vehicle and retrieve any codes that have been stored. If a P2402 code is present, they will use the tool to monitor sensor data and perform system tests to pinpoint the problem.

Perform a smoke test

A smoke test involves introducing inert smoke into the EVAP system to identify any leaks or damaged components. The mechanic will connect a smoke machine to the system and observe where the smoke is escaping from.

EVAP system emissions pressure test

A pressure test involves measuring the pressure in the EVAP system using a pressure gauge. The mechanic will connect the gauge to the system and monitor the pressure to determine if it falls outside of the manufacturer’s specifications.

How to fix the P2402 code

Once you have identified the cause of the P2402 code, you will need to take steps to fix the issue. Depending on the specific cause of the problem you can apply one of the following solutions as recommended by our team’s experts:

Replace the EVAP pressure sensor

If the EVAP system pressure sensor is found to be faulty during diagnosis, it will need to be replaced. The mechanic will disconnect the old sensor and install a new one in its place.

Repair damaged hoses

If the visual inspection or smoke test reveals that there are damaged or leaking hoses in the EVAP system, they will need to be repaired or replaced. You can patch small leaks but may need to replace entire hoses if they are severely damaged.

Tightening the fuel cap

If the fuel cap is found to be loose or damaged during diagnosis, it will need to be tightened or replaced which may help erase the code in case that’s what caused it in the first place.

Repairing or replacing the purge valve

If the purge valve is found to be faulty during diagnosis, it will need to be repaired or replaced. The mechanic will disconnect the old valve and install a new one in its place.

How to prevent the P2402 code

One of the best ways to prevent the P2402 code from occurring is to properly maintain the evaporative emission system. This may include making the following adjustments or maintenance tasks:

• Regularly check the gas cap for damage or looseness
• Inspect the fuel tank for corrosion
• Perform routine maintenance on the system

Additionally, it’s important to be aware of the potential causes of the P2402 code and take steps to address any issues as soon as they arise. By being proactive about maintaining your vehicle’s evaporative emission system, you can help prevent the P2402 code from occurring and ensure that your car runs smoothly and efficiently.

Our take

Without the properly working EVAP system, your car won’t be able to turn harmful gasses into much safer exhaust gases and this may affect the eco-friendly aspect of your driving. Plus, you may not be able to pass the emissions test, so we hope this guide was helpful when giving you advice on sorting out the issue and motivating you to take an instant action to prevent having to deal with increased emissions.