The P0440 trouble code is associated with an Evaporative Emission Control System Malfunction, indicating a problem within the vehicle’s emissions control system, particularly related to the fuel vapor recovery system.
Evaporative Emission Control System Malfunction
Code symptoms P0440.
1. Illuminated “Check Engine” or “Service Engine Soon” light on the dashboard.
2. Strong fuel odor near the vehicle.
3. Rough engine idle or stalling.
4. Decreased fuel efficiency.
This code is common in brands such as:: Chevrolet, Renault, Ford, Toyota, Nissan, Mercedes Benz, Honda.
Causes of the code P0440.
1. Loose or damaged fuel cap.
2. Faulty EVAP (Evaporative Emission Control) system components such as purge valve, vent valve, or charcoal canister.
3. Cracked or damaged hoses in the EVAP system.
4. ECM (Engine Control Module) issues.
Code Solutions P0440.
1. Ensure the fuel cap is securely tightened or replace it if damaged.
2. Test and, if necessary, replace faulty EVAP system components such as the purge valve, vent valve, or charcoal canister.
3. Inspect the EVAP system hoses for cracks or damage and repair or replace as needed.
4. If other potential causes are ruled out, consider diagnosing and possibly replacing the ECM.