Can You Drive Normally When the Engine Fault Light Is On?

[CameronLee]

The engine fault light comes in two colors: yellow and red. When the yellow fault light is on, you can continue driving. When the red fault light is on, you must stop driving immediately. When the yellow fault light is on, it serves as a warning, indicating that certain system parameters of the car may have exceeded the set range. The car can still be driven, but some functions may be limited. When the red fault 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 fault must be checked and addressed. There are seven main reasons why the engine fault light may come on: Sensor malfunction: This includes sensors such as the coolant temperature sensor, crankshaft position sensor, air flow sensor, intake 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 fault light. Fuel or oil quality issues: If you do not use the fuel or oil recommended by the manufacturer, it may cause engine wear and trigger the fault light. Poor combustion of the air-fuel mixture: Poor combustion can lead to engine carbon buildup or knocking. When detected by the oxygen sensor and reported to the ECU, the fault light will illuminate as a warning. Issues such as faulty spark plugs, ignition coils, fuel pumps, or clogged fuel lines can cause poor combustion. Turbocharger issues: Problems with the intake boost system or turbocharger can also trigger the engine fault light. The most common issue is a damaged turbocharger, which may also cause symptoms like oil leaks, excessive oil consumption, reduced power, metallic noises, or blue/black smoke from the exhaust. Intake issues: If the car's intake system is compromised, it may lead to clogged engine pipes, and in severe cases, the engine fault light will come on. A dirty or uncleaned air filter can cause intake problems. Exhaust issues: Exhaust system faults can also trigger the engine fault 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-containing oil additives, physical damage to the catalytic converter, or fuel system issues can all lead to catalytic converter failure. Anti-theft system malfunction: If the car's electronic anti-theft system malfunctions or the anti-theft controller is incompatible with the engine ECU, the anti-theft system may prevent the engine from operating normally, and the fault light will illuminate. If the engine fault light comes on, follow these steps: First, check if the engine is running normally. Look for signs of shaking, smoke, etc. If these are present, avoid restarting the engine. Note: If the red light is on, do not restart the engine under any circumstances. If the engine can be started, 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 perform a self-check when powered on. Wait 5-10 seconds and observe if the fault light turns off. If the fault light remains on, visit a service center as soon as possible. The service center can use a portable diagnostic tool to read the fault codes, identify the issue, and perform targeted repairs.

[RobertLee]

I just experienced the engine warning light coming on. Although the car was still drivable, it was definitely not a good sign. That light usually indicates an engine fault, such as an oxygen sensor issue or spark plug failure. You might be able to continue driving short distances, but it's highly risky—I once tried driving on the highway like this, only to have the engine overheat and break down, costing me a lot in towing and repair fees. After the light comes on, power decreases, fuel consumption increases, and the catalytic converter could be damaged. It's recommended to pull over immediately and check for simple causes like a loose fuel cap. If there's no improvement, use an OBD scanner to read the codes or take it to a professional shop. Avoid long-distance driving or sudden acceleration—safety should always come first.