What Does It Mean When the Car Engine Warning Light Comes On?
1 Answers
The engine warning light may illuminate due to the following 7 main reasons: Sensor Malfunction: The sensors referred to here include those for coolant temperature, crankshaft position, air flow, intake temperature, and oxygen sensors. When these sensors are damaged, have poor connections, or experience signal interruptions, the car's ECU cannot accurately obtain engine data, triggering the engine warning light. Fuel or Oil Quality Issues: Failure to use the fuel or engine oil as recommended by the manufacturer may cause engine wear, leading to the warning light activation. Poor Combustion of Air-Fuel Mixture: Inefficient combustion can result in engine carbon buildup or knocking. When detected by the oxygen sensor and reported to the ECU, the warning light will illuminate as a warning. Issues such as faulty spark plugs, ignition coils, fuel pumps, or clogged fuel lines can all cause poor combustion. Turbocharger Problems: Issues with the intake boost piping or turbocharger can also trigger the engine warning light. The most common issue is turbocharger damage, often accompanied by symptoms like oil leaks, excessive oil consumption, reduced power, metallic noises, or blue/black smoke from the exhaust. Intake Problems: If the car's intake system is compromised, it may lead to clogged engine pipes, and in severe cases, the engine warning light will come on. A dirty or uncleaned air filter can cause intake issues. Exhaust Problems: Exhaust system faults can also activate the engine warning light. Common causes include faulty rear oxygen sensors, catalytic converters, exhaust camshafts, or bearings. The catalytic converter is the most frequent culprit, often damaged by leaded gasoline, improper lubricant additives, physical impacts, or fuel system malfunctions. 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 system may prevent the engine from operating normally, accompanied by the warning light. If the engine warning light comes on, follow these steps: First, check whether the engine is running normally—look for symptoms like shaking or black smoke. If present, avoid restarting the engine. Note: Never restart the engine if the light is red. 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-diagnostic mode. After 5-10 seconds, check if the warning light turns off. If the light remains on, visit a service center as soon as possible. Technicians can use a diagnostic tool to read the trouble codes, identify the issue, and perform targeted repairs.
