<ul> <li><b>Engine Light ON (or Service Engine Soon Warning Light)</b>: The illumination of the engine light indicates a problem with the evaporative emission system. This is often linked to a low signal in the leak detection pump sense circuit.</li> <li><b>Increased Emissions</b>: A malfunction in the evaporative emission system can lead to increased emissions due to the inability to properly detect and manage fuel vapor leaks.</li> <li><b>Fuel Odor</b>: A noticeable fuel odor may be present due to the evaporative emission system's failure to contain fuel vapors, which could be caused by a faulty leak detection pump.</li> <li><b>Poor Fuel Economy</b>: The vehicle may experience reduced fuel efficiency as the evaporative emission system is not functioning optimally, potentially due to a low signal in the leak detection pump sense circuit.</li> </ul>

<ul><li>The leak detection pump may be faulty, leading to incorrect readings and triggering the error code.</li><li>An open or shorted harness in the leak detection pump can disrupt the signal, causing the system to malfunction.</li><li>Poor electrical connections in the leak detection pump circuit can result in intermittent or failed communication.</li><li>A faulty purge valve can affect the pressure and flow within the evaporative emission system, leading to errors.</li><li>A clogged or damaged charcoal canister can impede the system's ability to manage fuel vapors, causing the error code to appear.</li></ul>

<ul> <li><b>Initial Inspection</b>: Inspect the EVAP system for any visible damage or disconnections in hoses and connectors.</li> <li><b>Check Electrical Connections</b>: Verify that all electrical connections to the Leak Detection Pump (LDP) are secure and free of corrosion.</li> <li><b>Test Voltage Supply</b>: Using a multimeter, check the voltage supply to the LDP. Ensure it matches the manufacturer's specifications.</li> <li><b>Inspect Ground Circuit</b>: Check the ground circuit for continuity. A poor ground can cause a low sense circuit.</li> <li><b>Check LDP Resistance</b>: Measure the resistance of the LDP. Compare the readings with the manufacturer's specifications to ensure the pump is functioning correctly.</li> <li><b>Inspect Control Module</b>: Examine the Engine Control Module (ECM) for any signs of damage or malfunction that could affect the LDP circuit.</li> <li><b>Perform Smoke Test</b>: Conduct a smoke test to identify any leaks in the EVAP system that could be causing the issue.</li> <li><b>Clear DTC and Test Drive</b>: After repairs, clear the DTC and perform a test drive to ensure the issue is resolved and the code does not reappear.</li></ul>

<p>The DTC code P2405 indicates an issue with the Evaporative Emission System Leak Detection Pump Sense Circuit being low. This can lead to increased emissions and potential fuel vapor leaks.</p><ul><li><b>Immediate Actions:</b> Inspect the wiring and connections to the leak detection pump.</li><li>Check for any signs of damage or corrosion.</li><li>Replace the leak detection pump if necessary.</li></ul><p>Delaying repair can result in failed emissions tests and potential environmental harm.</p>