P0440 Fault Code

Evaporative Emission Control System Malfunction

• What does that mean?
• Symptoms
• Causes
• Solutions

The P0440 fault code indicates a malfunction within the evaporative emission control system (EVAP). This system is responsible for preventing gasoline vapors from escaping into the atmosphere. A properly functioning EVAP system helps to reduce emissions and improve fuel efficiency. When the P0440 code is triggered, it typically means that there is a leak, blockage, or failure in one of the components of the EVAP system.

What are the symptoms of the P0440 code?

Drivers may experience the following symptoms when the P0440 code is present:

• Check Engine Light illuminated on the dashboard
• Decrease in fuel economy
• Gasoline smell near the vehicle
• Difficulty filling the gas tank (due to pressure issues)
• Potential for increased emissions during vehicle inspection

What causes the P0440 code?

Common causes of the P0440 code include:

• Loose or damaged gas cap
• Cracked or damaged EVAP hoses
• Faulty EVAP canister
• Failed purge or vent valves
• Problems with the fuel tank or fuel filler neck
• A malfunctioning engine control module (ECM)

How to fix P0440?

To resolve the P0440 fault code, consider the following steps:

• Inspect and tighten or replace the gas cap if it is loose or damaged.
• Check the EVAP hoses for cracks or leaks and replace them as necessary.
• Test the operation of the EVAP purge and vent valves and replace any faulty components.
• Examine the EVAP canister for damage and replace it if needed.
• Make sure there are no leaks in the fuel tank or filler neck.
• Clear the fault codes and conduct a readiness test to ensure the issue is resolved.