<ul> <li><b>Engine Light ON (or Service Engine Soon Warning Light)</b>: <b>Engine Light ON</b> indicates a problem with the exhaust valve control circuit for cylinder 9. This can be caused by <ul><li>faulty exhaust valve control solenoid</li><li>damaged wiring or connectors</li><li>ECM/PCM issues</li></ul></li> <li><b>Reduced Engine Performance</b>: <b>Reduced Engine Performance</b> may occur due to improper exhaust valve operation, leading to inefficient combustion and power loss. Potential causes include <ul><li>exhaust valve control solenoid failure</li><li>electrical issues in the control circuit</li></ul></li> <li><b>Rough Idling</b>: <b>Rough Idling</b> can result from the exhaust valve not opening or closing properly, affecting the engine's air-fuel mixture. This can be linked to <ul><li>faulty solenoid</li><li>wiring issues</li></ul></li> <li><b>Increased Emissions</b>: <b>Increased Emissions</b> may be observed due to incomplete combustion caused by the malfunctioning exhaust valve. This can be attributed to <ul><li>exhaust valve control circuit issues</li><li>solenoid failure</li></ul></li> </ul>

<ul><li>Low oil pressure can lead to insufficient lubrication and improper functioning of the exhaust valve control circuit.</li><li>Restricted oil passage may prevent adequate oil flow, affecting the operation of the cylinder deactivation system.</li><li>Engine mechanical condition issues, such as worn components, can disrupt the exhaust valve control circuit.</li><li>A faulty Cylinder Deactivation Solenoid can fail to regulate the exhaust valve properly.</li><li>An open or shorted Cylinder Deactivation Solenoid harness can cause electrical issues, leading to the error code.</li><li>Poor electrical connection in the Cylinder Deactivation Solenoid circuit can result in intermittent or failed operation.</li></ul>

<ul> <li><b>Research Technical Service Bulletins (TSBs)</b>: Research TSBs for the specific vehicle by year, model, and engine to identify any known fixes for this issue.</li> <li><b>Check Engine Oil Condition</b>: Verify the engine oil is at the appropriate level and in good condition. Low or dirty oil can affect the variable valve timing system.</li> <li><b>Locate Cylinder 9 Exhaust Valve Control Circuit Components</b>: Identify all components associated with the cylinder 9 exhaust valve control circuit, including the variable valve timing solenoid, switches, fault indicators, and the ECM.</li> <li><b>Perform Visual Inspection</b>: Inspect the associated wiring for defects such as scraping, rubbing, bare wires, or burn spots. Check connectors for security, corrosion, and damaged pins.</li> <li><b>Test Variable Valve Timing Solenoid</b>: Test the variable valve timing solenoid for proper operation. Replace if faulty.</li> <li><b>Clean Corroded Connectors</b>: Clean any corrosion from connectors to ensure proper electrical contact.</li> <li><b>Repair or Replace Faulty Wiring</b>: Repair or replace any damaged wiring in the circuit.</li> <li><b>Clear Blocked Oil Passages</b>: Check for and clear any blocked oil passages that could affect the variable valve timing system.</li> <li><b>Flash or Replace ECM</b>: If all other components are functioning correctly, consider flashing or replacing the ECM.</li> <li><b>Clear DTC and Test Drive</b>: Clear the DTC code and perform a test drive to ensure the issue is resolved.</li></ul>

<p>The DTC code P3471 indicates a <b>Cylinder 9 Exhaust Valve Control Circuit Low</b> issue. This is a critical problem as it affects engine performance and emissions. Immediate actions should include:</p><ul><li>Inspecting the exhaust valve control circuit for faults.</li><li>Checking wiring and connections for damage or corrosion.</li><li>Testing the exhaust valve actuator for proper operation.</li></ul><p>Delaying repair can lead to severe engine damage and increased emissions.</p>