<ul> <li><b>Engine Light ON (or Service Engine Soon Warning Light)</b>: The illumination of the engine light indicates a detected issue within the Exhaust Gas Recirculation (EGR) Cooler Bypass Control Circuit. This could be due to a malfunctioning EGR cooler bypass valve, wiring issues, or a faulty EGR temperature sensor.</li> <li><b>Reduced Engine Performance</b>: The vehicle may experience reduced power and acceleration due to improper EGR operation, which can affect the engine's efficiency and emissions control.</li> <li><b>Increased Emissions</b>: A malfunctioning EGR system can lead to higher emissions of NOx and other pollutants, as the EGR system is crucial for reducing these emissions.</li> <li><b>Engine Overheating</b>: Improper EGR cooler operation can result in higher engine temperatures, potentially leading to overheating issues.</li> </ul>

<ul><li>Issues within the coolant system can lead to improper cooling and affect the EGR cooler's performance.</li><li>Malfunctioning EGR cooler can cause incorrect exhaust gas temperatures, triggering the code.</li><li>A faulty EGR temperature sensor may provide inaccurate readings, leading to performance issues.</li><li>An open or shorted EGR temperature sensor harness can disrupt the signal, causing the control circuit to malfunction.</li><li>Poor electrical connections in the EGR temperature sensor circuit can result in intermittent or incorrect signals, affecting the system's performance.</li></ul>

<ul> <li><b>Research Technical Service Bulletins (TSBs)</b>: Research TSBs for the specific vehicle by year, model, and power plant to identify any known issues or updates related to the EGR cooler bypass control circuit.</li> <li><b>Locate EGR Cooler Bypass Components</b>: Identify and locate all components associated with the EGR cooler bypass circuit, including the temperature switch, bypass valve, EGR valve, EGR cooler, and ECM.</li> <li><b>Perform Visual Inspection</b>: Conduct a thorough visual inspection of the EGR cooler bypass circuit components. Look for obvious physical damage, such as scraping, rubbing, bare wires, or burn spots.</li> <li><b>Check Connectors and Connections</b>: Inspect all connectors and connections for security, corrosion, and damaged pins. Ensure all wiring connections to the EGR temperature switch and ECM are secure and free of corrosion.</li> <li><b>Verify Circuit Configuration</b>: Consult the specific technical data for the vehicle to verify the configuration of the EGR cooler bypass valve control circuit. Confirm every component incorporated within the circuit, including any fuses or fuse-able links.</li> <li><b>Test EGR Cooler Bypass Valve</b>: Test the EGR cooler bypass valve for proper operation. Replace if found faulty.</li> <li><b>Test Temperature Switch</b>: Test the EGR temperature switch for proper functionality. Replace if necessary.</li> <li><b>Inspect and Clean Connectors</b>: Clean any corrosion from connectors and ensure they are making good contact.</li> <li><b>Check and Repair Wiring</b>: Inspect the wiring for any faults. Repair or replace any damaged wiring as needed.</li> <li><b>Clean Carbon Buildup</b>: Clean any carbon buildup in the EGR system components to ensure proper flow and operation.</li> <li><b>Flash or Replace ECM</b>: If all other components are functioning correctly, consider flashing or replacing the ECM to resolve any control circuit issues.</li></ul>

<p>The DTC code P245B indicates an issue with the Exhaust Gas Recirculation (EGR) Cooler Bypass Control Circuit. This can lead to improper EGR operation, affecting engine performance and emissions.</p><ul><li><b>Immediate Actions:</b> Inspect the EGR cooler bypass valve and control circuit for faults.</li><li><b>Potential Risks:</b> Delayed repair can result in increased emissions, reduced fuel efficiency, and potential engine damage.</li></ul>