<ul> <li><b>Engine Light ON (or Service Engine Soon Warning Light)</b>: The illumination of the engine light indicates a problem with the exhaust gas recirculation (EGR) cooler bypass control circuit. This can be caused by a faulty EGR cooler bypass valve, wiring issues, or a malfunctioning control module.</li> <li><b>Reduced Engine Performance</b>: A malfunctioning EGR cooler bypass control circuit can lead to reduced engine performance due to improper exhaust gas recirculation, affecting combustion efficiency.</li> <li><b>Increased Emissions</b>: Improper functioning of the EGR system can result in increased NOx emissions, as the exhaust gases are not being recirculated effectively.</li> <li><b>Engine Overheating</b>: A faulty EGR cooler bypass can cause the engine to overheat due to improper cooling of the exhaust gases.</li> </ul>

<ul><li>Coolant system issues can lead to improper cooling, affecting the EGR cooler's performance.</li><li>Malfunctioning EGR cooler can cause the bypass control circuit to register low.</li><li>A faulty EGR temperature sensor may provide incorrect readings, triggering the error code.</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 lead to intermittent or incorrect signals, resulting in the error code.</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 Circuit 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>: Using a multimeter, test the EGR cooler bypass valve for proper operation. Check for continuity and proper resistance values as specified in the vehicle's service manual.</li> <li><b>Inspect and Clean Connectors</b>: Clean any corrosion from connectors and ensure they are making proper contact. Use electrical contact cleaner if necessary.</li> <li><b>Check and Repair Wiring</b>: Inspect the wiring for any faults or damage. Repair or replace any faulty wiring as needed.</li> <li><b>Test Temperature Switch</b>: Test the EGR temperature switch for proper operation. Replace if it is found to be faulty.</li> <li><b>Check for Carbon Buildup</b>: Inspect the EGR cooler and bypass valve for carbon buildup. Clean as necessary to ensure proper operation.</li> <li><b>ECM Flash or Replacement</b>: If all other components are functioning correctly, consider flashing or replacing the ECM as a last resort.</li></ul>

<p>The DTC code P245C indicates an issue with the Exhaust Gas Recirculation (EGR) Cooler Bypass Control Circuit being low. This can lead to improper EGR function, 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 and potential engine damage.</li></ul>