Can You Still Drive When the Engine Fault Light Comes On?
3 Answers
Engine fault lights come 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 illuminated, it serves as a warning, indicating that certain system parameters in the car may have exceeded the set range. The vehicle can still be driven, but some functions may be limited. When the red fault light is on, it indicates a serious fault, and the car must be stopped immediately. Turn off the engine, refrain from further driving, and check for the source of the fault. There are seven main reasons why the engine fault light may come on: Sensor malfunction: Sensors such as coolant temperature, crankshaft position, air flow, intake temperature, and oxygen sensors may become damaged, have poor contact, or lose signal. When the car's ECU cannot accurately obtain engine data, the engine fault light will illuminate. Fuel or oil quality issues: If fuel or engine oil is not added according to the manufacturer's requirements, it may cause engine wear, leading to the fault light turning on. 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 problems: Issues with the intake boost pipes or turbocharger can also trigger the engine fault light. The most common problem is a damaged turbocharger, often accompanied by symptoms such as oil leaks, excessive oil consumption, reduced power, metallic noises, or blue/black smoke from the exhaust. Intake problems: If the car's air intake is compromised, it may lead to engine pipe blockages, which can trigger the fault light. A dirty air filter or lack of regular cleaning can cause intake issues. Exhaust problems: Exhaust system faults can also cause the engine fault light to illuminate. Common causes include faulty rear oxygen sensors, catalytic converters, exhaust camshafts, or bearings. The catalytic converter is the most frequent issue, often due to the use of leaded gasoline, lead- or silicon-containing oil additives, physical damage, 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 engine may not function properly, and the fault light will turn on. If the engine fault light comes on, follow these steps: First, check whether the engine is running normally. If there are issues such as shaking or smoke, 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, and after 5-10 seconds, check whether the fault light has turned off. If the fault 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.
When driving, I pay special attention to the dashboard, and the moment the engine warning light comes on, I immediately feel alarmed. From a safety perspective, this light is definitely a warning signal, indicating potential serious engine issues such as overheating, oil leaks, or sensor malfunctions. Continuing to drive could turn minor problems into catastrophic engine failure, which would be disastrous, especially on highways. I always advise friends to find a safe place to pull over immediately and avoid risky driving. It’s best to use a phone to locate nearby repair shops and call for a tow truck or drive slowly for inspection. Remember, lives are far more important than the car. Develop the habit of checking engine oil and coolant every 1,000 kilometers—it significantly reduces the risk of breakdowns.
As someone who enjoys tinkering with cars, I always want to figure out the reason immediately when the engine warning light comes on. This light could indicate issues like a faulty oxygen sensor, a clogged catalytic converter, or problems with the fuel system. Technically speaking, some minor faults might still allow you to drive a short distance to the repair shop, but you must keep the speed low and avoid stomping on the accelerator; however, the risks are significant, such as the engine completely stalling or even catching fire if you push it. I strongly recommend keeping an OBD diagnostic tool in your car—just plug it in to read the trouble codes and understand the problem. Addressing issues early can save you a lot on repair costs; for example, replacing a sensor might only cost a few hundred bucks, while delaying could lead to thousands in major repairs. It's safest to take it to a professional shop for a proper fix.
