<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 <causes> such as a faulty EGR cooler bypass valve, damaged wiring, or a malfunctioning control module.</li> <li><b>Reduced Engine Performance</b>: The vehicle may experience reduced engine performance due to improper EGR operation. This can be linked to <causes> such as a stuck EGR cooler bypass valve or issues within the control circuit.</li> <li><b>Increased Emissions</b>: Higher emissions may be observed as a result of the EGR system not functioning correctly. Potential <causes> include a malfunctioning EGR cooler bypass valve or high resistance in the control circuit.</li> </ul>

<ul><li>Faulty Exhaust Gas Recirculation (EGR) Cooler Bypass Valve can lead to improper regulation of exhaust gases, causing high voltage in the control circuit.</li><li>An open or shorted EGR Cooler Bypass Valve harness can disrupt the electrical flow, resulting in high voltage readings.</li><li>Poor electrical connection in the EGR Cooler Bypass Valve circuit can cause intermittent or high resistance, leading to voltage issues.</li><li>A malfunctioning Engine Control Module (ECM) can incorrectly interpret or send signals, causing high voltage in the EGR Cooler Bypass Control Circuit.</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 Voltage and Continuity</b>: Use a multimeter to test for proper voltage and continuity in the EGR cooler bypass control circuit. Check for high voltage readings that may indicate a fault.</li> <li><b>Inspect and Clean Components</b>: Inspect the EGR cooler, bypass valve, and temperature switch for carbon buildup or corrosion. Clean or replace components as necessary.</li> <li><b>Check and Repair Wiring</b>: Examine the wiring for any faults or damage. Repair or replace faulty wiring as needed.</li> <li><b>Flash or Replace ECM</b>: If all other components and wiring are in good condition, consider flashing or replacing the ECM to resolve the issue.</li></ul>

<p>The DTC code P245D indicates a high voltage issue in the Exhaust Gas Recirculation (EGR) Cooler Bypass Control Circuit. 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 related wiring for faults.</li><li><b>Potential Risks:</b> Delayed repair can result in increased emissions and potential engine damage.</li></ul>