The engine warning light comes in two colors: yellow and red. When the yellow warning light is on, you can continue driving. When the red warning light is on, you must stop driving immediately. When the yellow warning light is on, it serves as a warning, indicating that certain system parameters of the car may be outside the set range. The car can still be driven at this time, but some functions may be limited. When the red warning light is on, it means the fault is severe. The car must be stopped immediately, the engine turned off, and driving must not continue. The issue causing the fault should be checked. There are seven main reasons why the engine warning light may come on: 1. Sensor malfunction: This includes sensors such as the coolant temperature sensor, crankshaft position sensor, air flow sensor, intake air temperature sensor, and oxygen sensor. If these sensors are damaged, have poor contact, or their signals are interrupted, the car's ECU cannot accurately obtain engine data, triggering the engine warning light. 2. Fuel or oil quality issues: If the fuel or engine oil does not meet the manufacturer's specifications, it may cause engine wear and trigger the warning light. 3. Poor fuel mixture combustion: Poor combustion can lead to engine carbon buildup or knocking. When detected by the oxygen sensor and reported to the ECU, the warning light will illuminate. Issues such as faulty spark plugs, ignition coils, fuel pumps, or clogged fuel lines can cause poor combustion. 4. Turbocharger problems: Issues with the intake boost pipes or turbocharger can also trigger the engine warning light. The most common issue is a damaged turbocharger, accompanied by symptoms like oil leaks, excessive oil consumption, reduced power, metallic noises, or blue/black smoke from the exhaust. 5. Intake problems: If the car's intake system is compromised, it may lead to clogged engine pipes, and in severe cases, trigger the warning light. A dirty or uncleaned air filter can cause intake issues. 6. Exhaust problems: Exhaust system faults can also trigger the warning light. Common causes include faulty rear oxygen sensors, catalytic converters, exhaust camshafts, or bearings. The catalytic converter is the most frequent culprit. Using leaded gasoline, lead- or silicon-based oil additives, physical damage to the catalytic converter, or fuel system issues can all lead to catalytic converter failure. 7. Anti-theft system malfunction: If the car's electronic anti-theft system fails or the anti-theft controller does not match the engine ECU, the anti-theft system may prevent the engine from operating normally, triggering the warning light. If the engine warning light comes on, follow these steps: 1. First, check if the engine is running normally. Look for signs of shaking, smoke, etc. If present, avoid restarting the engine. Note: If the red light is on, do not restart the engine under any circumstances. 2. If the engine can start, turn it off and wait 5-10 minutes. Without pressing the brake, press the start button once or turn the key halfway to the 'ON' position (without pressing the clutch). The car will enter self-diagnosis mode. Wait 5-10 seconds and observe if the warning light turns off. 3. If the warning light remains on, visit a service center as soon as possible. Technicians can use a diagnostic tool to read the fault code, identify the issue, and perform targeted repairs.
