What causes the engine warning light to illuminate in the XC60?

[MacLouis]

The engine warning light may illuminate during power-on self-test or under other circumstances. The power-on self-test is an indicator that monitors the status of all vehicle sensors before driving. Generally, if the vehicle is not started after power-on, the light will turn off automatically after about 3 seconds. In other cases, if the EPC warning light remains illuminated after the vehicle is started, the main causes may include engine misfire, anti-theft system failure, exhaust issues, turbocharging problems, intake issues, poor fuel mixture combustion, fuel quality problems, maintenance issues, or sensor malfunctions. Below is a detailed explanation of each potential issue: Sensor issues: Sensors include coolant temperature, crankshaft position, air flow, intake temperature, oxygen sensors, etc. When these sensors are damaged, have poor contact, or experience signal interruptions, the vehicle's ECU cannot accurately obtain engine data, which may trigger the engine warning light. Solution: If such issues occur, promptly visit a repair center for professional inspection to eliminate potential safety hazards. Maintenance issues: Poor engine maintenance is the most common cause of the engine warning light. Vehicles have specific maintenance cycles. If maintenance is neglected and combined with poor driving habits, the engine's operational burden increases, eventually triggering the warning light to alert the owner of a fault. Solution: Follow the time or mileage intervals specified in the vehicle's maintenance manual to ensure comprehensive maintenance and rule out non-maintenance-related issues. Fuel quality issues: This refers to both fuel and engine oil. Vehicles require specific fuel grades, and engine oil can be semi-synthetic or fully synthetic. Manufacturers typically recommend the appropriate fuel grade and oil type. Failure to adhere to these recommendations can lead to engine wear over time, triggering the warning light. Solution: Use the recommended fuel grade and suitable engine oil for the vehicle. Poor fuel mixture combustion: Faulty spark plugs, fuel pump issues, or clogged fuel lines can cause poor fuel mixture combustion. This leads to engine carbon buildup or knocking, which the oxygen sensor detects and reports to the ECU, triggering the warning light. Solution: Regularly inspect and clean spark plugs, replace components as needed, clean carbon deposits, and maintain the engine properly. Intake issues: Engine combustion requires air intake, making the air filter crucial. A dirty or clogged air filter can restrict airflow, potentially leading to blockage and triggering the engine warning light. Solution: Regularly clean or replace the air filter to ensure the intake system functions properly. Turbocharging issues: Problems with the intake turbocharging pipes or turbocharger can also trigger the engine warning light. Common issues include turbocharger damage, accompanied by symptoms like oil leaks, excessive oil consumption, reduced power, metallic noises, or blue/black smoke from the exhaust. Solution: Visit a 4S shop to inspect and replace the turbocharger. Repairing such issues is often not cost-effective, so replacement is usually recommended. Exhaust issues: Faults in the rear oxygen sensor, catalytic converter, or exhaust camshaft and bearings can trigger the warning light. The most common issue is catalytic converter failure, often caused by physical damage or fuel system problems. Solution: Use lead- or silicon-based lubricants to maintain and clean the catalytic converter. Anti-theft system: If the vehicle's electronic anti-theft system malfunctions or the anti-theft controller is incompatible with the engine ECU, the engine may not operate correctly, and the warning light may illuminate. Solution: Seek professional assistance at a repair shop, as this issue cannot be resolved individually. Engine misfire: This occurs when one or more cylinders fail to operate properly, leading to symptoms like reduced power, difficulty starting, or unstable idling. Solution: Identify and replace faulty cylinder components. If internal mechanical damage occurs, a major repair at a professional shop may be necessary.