<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 high-pressure fuel pump. This could be due to a malfunctioning pump, fuel delivery problems, or sensor issues.</li> <li><b>Engine Stalling or Hesitation</b>: The engine may stall or hesitate during acceleration, which can be caused by insufficient fuel pressure due to a failing high-pressure fuel pump.</li> <li><b>Reduced Engine Performance</b>: A noticeable drop in engine performance, such as reduced power or acceleration, can occur if the high-pressure fuel pump is not delivering adequate fuel to the engine.</li> <li><b>Difficulty Starting the Engine</b>: The engine may be hard to start or may not start at all if the high-pressure fuel pump is unable to maintain the necessary fuel pressure.</li> <li><b>Fuel Odor</b>: A strong smell of fuel may be present if there is a leak in the high-pressure fuel system, which can be a symptom of a failing high-pressure fuel pump.</li> </ul>

<ul><li>The high pressure fuel pump may be malfunctioning, leading to insufficient fuel pressure.</li><li>There could be an open or shorted condition in the high pressure fuel pump harness, disrupting the electrical flow.</li><li>Poor electrical connections in the high pressure fuel pump circuit can cause intermittent or complete loss of power to the pump.</li></ul>

<ul> <li><b>Initial Scan</b>: Use an OBD-II scanner to confirm the presence of DTC P3090 and check for any additional codes that may be related.</li> <li><b>Visual Inspection</b>: Inspect the high-pressure fuel pump and its connections for any visible signs of damage, leaks, or loose connections.</li> <li><b>Fuel Pressure Test</b>: Measure the fuel pressure at the high-pressure fuel pump using a fuel pressure gauge. Compare the readings with the manufacturer's specifications.</li> <li><b>Electrical Check</b>: Verify the electrical connections to the high-pressure fuel pump. Check for proper voltage and ground at the pump connector.</li> <li><b>Fuel Pump Relay and Fuse</b>: Inspect the fuel pump relay and fuse for proper operation. Replace if necessary.</li> <li><b>Fuel Quality Check</b>: Examine the fuel for contamination or water. Poor fuel quality can affect the performance of the high-pressure fuel pump.</li> <li><b>ECU Check</b>: Check the Engine Control Unit (ECU) for any software updates or known issues related to the high-pressure fuel pump.</li> <li><b>Component Replacement</b>: If all tests indicate a faulty high-pressure fuel pump, proceed with replacing the pump and clearing the DTC code. Re-test to ensure the issue is resolved.</li></ul>

<p>The DTC code P3090 indicates an issue with the high-pressure fuel pump. This is a critical problem as it can lead to severe engine performance issues or complete engine failure.</p><ul><li><b>Immediate Actions:</b> Inspect and replace the high-pressure fuel pump if necessary.</li><li><b>Potential Risks:</b> Delayed repair can result in engine stalling, poor fuel economy, and potential damage to other engine components.</li></ul>