DTC Code P2404 – What does this code mean?

<ul> <li><a href="/problems/vw-check-engine-light-is-on"><b>Engine Light ON</b></a>: The check engine light or service engine soon warning light illuminates, indicating an issue with the evaporative emission system. This is often linked to a malfunction in the leak detection pump sense circuit.</li> </ul>

<ul><li>The leak detection pump may be faulty, leading to incorrect pressure readings within the evaporative emission system.</li><li>An open or shorted harness in the leak detection pump can disrupt the electrical signals, causing performance issues.</li><li>Poor electrical connections in the leak detection pump circuit can result in intermittent or weak signals, affecting system performance.</li><li>A faulty purge valve can prevent proper venting of the fuel vapor, leading to pressure imbalances in the system.</li><li>A clogged or damaged charcoal canister can restrict vapor flow, causing pressure issues and triggering the error code.</li></ul>

<ul> <li><b>Verify DTC Code</b>: Ensure the DTC P2404 is active by using a diagnostic scanner. Clear the code and perform a test drive to see if it returns.</li> <li><b>Inspect EVAP System Components</b>: Visually inspect the EVAP system components, including hoses, connectors, and the leak detection pump for any signs of damage or disconnection.</li> <li><b>Check Electrical Connections</b>: Examine the electrical connections to the leak detection pump. Ensure there are no loose, corroded, or damaged wires and connectors.</li> <li><b>Test Leak Detection Pump</b>: Use a multimeter to test the leak detection pump's electrical circuit. Check for proper voltage and ground at the pump connector.</li> <li><b>Perform Smoke Test</b>: Conduct a smoke test to identify any leaks in the EVAP system. Pay special attention to the areas around the leak detection pump.</li> <li><b>Check ECM Functionality</b>: Verify the Engine Control Module (ECM) is functioning correctly and is not causing false readings. Reprogram or replace if necessary.</li> <li><b>Re-evaluate and Clear Codes</b>: After repairs, clear the DTC and perform a test drive to ensure the issue is resolved and the code does not return.</li></ul>

<p>The DTC P2404 for Volkswagen indicates an issue with the <b>Evaporative Emission System Leak Detection Pump Sense Circuit</b>. This is a <b>moderate</b> issue as it affects the vehicle's emission control system. If left unaddressed, it may lead to increased emissions and potential failure of emission tests. Immediate attention is advised to prevent further environmental impact and ensure compliance with emission standards.</p>