<ul> <li><b>Engine Light ON (or Service Engine Soon Warning Light)</b>: The illumination of the engine light indicates a detected issue with the supply relay for engine components. This could be due to a malfunctioning relay, poor electrical connections, or a fault in the engine control module (ECM).</li> <li><b>Engine Performance Issues</b>: The vehicle may experience reduced power, stalling, or difficulty starting. These symptoms are linked to the supply relay failing to provide consistent power to essential engine components.</li> <li><b>Electrical Malfunctions</b>: Other electrical components related to the engine may exhibit erratic behavior or fail to operate. This is often caused by intermittent or complete failure of the supply relay.</li> </ul>

<ul><li>Inspect the main battery cables for any signs of corrosion, damage, or loose connections, as these can disrupt the power supply to engine components.</li><li>Check the battery's state of charge and overall health, as a weak or failing battery can lead to insufficient power being supplied to the engine components.</li></ul>

<ul> <li><b>Initial Scan</b>: Use an OBD-II scanner to confirm the presence of DTC P3087 and check for any additional codes that may be related.</li> <li><b>Visual Inspection</b>: Inspect the supply relay for engine components for any visible damage, corrosion, or loose connections.</li> <li><b>Relay Function Test</b>: Test the relay using a multimeter to ensure it is functioning correctly. Check for continuity and proper operation.</li> <li><b>Check Power Supply</b>: Verify that the relay is receiving the correct voltage from the power supply. Use a multimeter to measure the voltage at the relay terminals.</li> <li><b>Inspect Wiring and Connectors</b>: Examine the wiring and connectors associated with the relay for any signs of wear, damage, or corrosion. Repair or replace as necessary.</li> <li><b>Test Engine Components</b>: Check the engine components that are powered by the relay to ensure they are functioning properly. This may include fuel injectors, ignition coils, and other related components.</li> <li><b>ECU Check</b>: Verify that the Engine Control Unit (ECU) is sending the correct signals to the relay. Use a diagnostic tool to check for proper ECU operation.</li> <li><b>Clear Codes and Test Drive</b>: After performing the necessary repairs, clear the DTC codes and conduct a test drive to ensure the issue has been resolved and the code does not reappear.</li></ul>

<p>The DTC code P3087 indicates an issue with the supply relay for engine components. This is a critical issue as it can lead to engine stalling or failure to start. Immediate actions should include:</p><ul><li>Inspecting the relay and associated wiring for damage or corrosion.</li><li>Testing the relay for proper operation.</li><li>Replacing the relay if found faulty.</li></ul><p>Delaying repair can result in severe engine performance issues and potential safety hazards.</p>