P0440 Code - Evaporative Emission Control System Malfunction
Quick Answer
The Engine Control Module (ECM) tests the Evaporative Emission (EVAP) system for the following conditions: - Large and small leaks - Excess vacuum - Purge flow during non-commanded conditions - Fuel Level and Fuel Pressure sensor faults - EVAP Purge and Vent Valve faults The ECM monitors the Fuel Tank Pressure sensor in order to determine the level of vacuum/pressure in the EVAP system. Common causes include Missing or loose fuel cap, Incorrect fuel filler cap used, Fuel filler cap remains open or fails to close. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.
- What it means
- P0440 indicates Evaporative Emission Control System Malfunction.
- Common causes
- Common causes include Missing or loose fuel cap, Incorrect fuel filler cap used, Fuel filler cap remains open or fails to close.
- Severity
- Low - monitor the vehicle and repair when practical.
- Can I drive?
- The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.
Code P0440 Description
- Large and small leaks
- Excess vacuum
- Purge flow during non-commanded conditions
- Fuel Level and Fuel Pressure sensor faults
- EVAP Purge and Vent Valve faults
The ECM monitors the Fuel Tank Pressure sensor in order to determine the level of vacuum/pressure in the EVAP system. The ECM commands both the EVAP Purge Solenoid and the EVAP Vent Valve ON when the conditions are met in order to apply an engine vacuum to the EVAP system. The ECM commands the EVAP Purge Solenoid OFF once the system has reached a predetermined level of vacuum. This test verifies if a vacuum can be achieved in the EVAP system. Failure to develop a vacuum may be caused by a large leak or a restriction.
What are the Possible Causes of the DTC P0440?
- Missing or loose fuel cap
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close
- Foreign matter caught in fuel filler cap
- EVAP canister or fuel tank leaks
- EVAP system hose leaking
- Fuel tank leaking
How to Fix the DTC P0440?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
Code Tech Notes
User Submitted Video
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0440 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Information for Specific Makes
- P0440 Audi — EVAP Canister Purge Regulator Valve
- P0440 BMW — Tank Venting System Function
- P0440 Buick — Evaporative Emission System
- P0440 Cadillac — Evaporative Emission System
- P0440 Chevrolet — Evaporative Emission System
- P0440 Chrysler — General EVAP System Failure
- P0440 Dodge — General EVAP System Failure
- P0440 GMC — Evaporative Emission System
- P0440 Hyundai — Evaporative Emission Control System Malfunction
- P0440 Infiniti — EVAP Control System Small Leak
- P0440 Jeep — General EVAP System Failure
- P0440 KIA — Evaporative Emission Control System Malfunction
- P0440 Lexus — Evaporative Emission Control System Malfunction
- P0440 Mazda — Evaporative Emission System
- P0440 Mercedes-Benz — Evaporative Emission Control System Malfunction
- P0440 MINI — Tank Venting System Function
- P0440 Mitsubishi — EVAP Control System Malfunction
- P0440 Nissan — EVAP Control System Small Leak
- P0440 Oldsmobile — Evaporative Emission System
- P0440 Pontiac — Evaporative Emission System
- P0440 Saturn — Evaporative Emission System
- P0440 Scion — Evaporative Emission Control System Malfunction
- P0440 Toyota — Evaporative Emission Control System Malfunction
- P0440 Volkswagen — EVAP Canister Purge Regulator Valve
Frequently Asked Questions about P0440 Code
1. What are the common symptoms of OBDII code P0440?
The common symptoms of OBDII code P0440 include the illumination of the check engine light on the dashboard and a possible gasoline odor around the vehicle.
2. What are the potential causes of OBDII code P0440?
Potential causes of OBDII code P0440 may include a loose or damaged gas cap, a faulty EVAP system purge valve, a leak in the EVAP system, or a malfunctioning EVAP canister.
3. How serious is OBDII code P0440?
While OBDII code P0440 is not typically a critical issue that affects the drivability of the vehicle, it can lead to increased emissions and may cause the vehicle to fail an emissions test.
4. How can I diagnose the cause of OBDII code P0440?
To diagnose the cause of OBDII code P0440, you can start by checking the gas cap to ensure it is tight and in good condition. You may also need to inspect the EVAP system components for any visible damage or leaks.
5. Can I continue driving with OBDII code P0440?
It is generally safe to continue driving with OBDII code P0440, but it is recommended to have the issue diagnosed and repaired as soon as possible to prevent any potential long-term problems with the EVAP system.
6. How can I repair OBDII code P0440?
Repairing OBDII code P0440 may involve tightening or replacing the gas cap, replacing a faulty purge valve or canister, repairing leaks in the EVAP system, or clearing any blockages in the system.
7. Will resetting the check engine light fix OBDII code P0440?
Simply resetting the check engine light will not fix OBDII code P0440. It is important to diagnose the root cause of the code and address any underlying issues to prevent the code from reoccurring.
8. How much does it cost to repair OBDII code P0440?
The cost of repairing OBDII code P0440 can vary depending on the cause of the issue and the specific components that need to be repaired or replaced. Costs may range from a simple gas cap replacement to more extensive EVAP system repairs.
9. Can a DIY enthusiast fix OBDII code P0440?
A DIY enthusiast with some automotive knowledge and tools may be able to address OBDII code P0440, especially if it involves a straightforward fix like tightening the gas cap. However, more complex issues may require professional diagnosis and repair.
10. How can I prevent OBDII code P0440 from occurring in the future?
To prevent OBDII code P0440 from occurring in the future, it is essential to regularly inspect the gas cap for tightness and damage, perform routine maintenance on the EVAP system, and address any issues promptly to maintain the system's integrity.
Discuss the causes and fixes for P0440 OBDII Code
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After smoking my vehicle several times. The location was finally found. It was under the car near the rear of the fuel tank. There is a little valve which has a very tiny crack which needs replacing.
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I have a 02 Toyota 4Runner. What should I do first to get rid of this code? Mahalo for your help
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