Can You Drive with the Engine Malfunction Light On?
3 Answers
The engine malfunction light comes in two colors: yellow and red. When the yellow malfunction light is on, you can continue driving, but when the red malfunction light is on, you must stop driving immediately. When the yellow malfunction light is on, it serves as a warning, indicating that certain system parameters in the car may have exceeded the set range. The car can still be driven, but some functions may be limited. When the red malfunction light is on, it means the issue is severe. You must stop the car immediately, turn off the engine, and avoid further driving. Check for the cause of the malfunction. There are seven main reasons why the engine malfunction light may illuminate: 1. Sensor Failure: 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 connections, or lose signal, the car's ECU cannot accurately obtain engine data, triggering the malfunction light. 2. Fuel or Oil Quality Issues: If you do not use the fuel or oil specified by the manufacturer, it may cause engine wear and trigger the malfunction light. 3. Poor Combustion of the Air-Fuel Mixture: This can lead to engine carbon buildup or knocking. The oxygen sensor detects this and reports it to the ECU, which then lights the malfunction light as a warning. Issues such as faulty spark plugs, ignition coils, fuel pump, or clogged fuel lines can cause poor combustion. 4. Turbocharger Problems: Issues with the intake boost pipes or turbocharger can also trigger the malfunction light. The most common issue is a damaged turbocharger, which may also cause 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 clogged or malfunctioning, it may lead to engine issues and trigger the malfunction light. A dirty or uncleaned air filter can cause intake problems. 6. Exhaust Problems: Exhaust system failures, such as issues with the rear oxygen sensor, catalytic converter, or exhaust camshaft and bearings, can trigger the malfunction light. The catalytic converter is the most common culprit, especially if the car uses leaded gasoline, improper oil additives, or if the converter is damaged. 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 engine may not function properly, and the malfunction light may illuminate. If the engine malfunction light is on, follow these steps: 1. First, check if the engine is running normally. If there is shaking, smoke, or other issues, avoid restarting the engine. 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 to see if the malfunction light turns off. 3. If the light remains on, visit a service center as soon as possible. Technicians can use a diagnostic tool to read the error codes and identify the issue for targeted repairs.
Last time I took my old Buick on a long trip, I encountered this exact situation—the yellow warning light was blinking like an alarm clock. I gritted my teeth and drove 20 kilometers to the repair shop, where the mechanic told me the oxygen sensor had called it quits. Actually, warning lights come in different levels of severity: if the light stays on steadily but the car isn’t shaking, it’s probably just the exhaust system throwing a minor tantrum, and you can usually make it to the shop without much trouble. But if that yellow light is flashing like a strobe at a club, or the engine starts wheezing, pull over immediately! My neighbor Old Zhang once ignored the warning and kept driving on the highway with the light on—ended up stranded halfway, and the tow truck fee cost him enough to replace two sensors. My advice? Always keep an OBD scanner in your trunk. Plug it in, and it’ll read the trouble codes for you—no more driving on edge.
We veteran taxi drivers fear this warning light the most. If we see the yellow dashboard light on during morning shift handover, we head straight back to the depot for inspection. The engine is like the human heart, and the warning light is its ECG. I've seen colleagues who kept driving with the light on - three days later they needed an 8,000-yuan engine overhaul. Modern car computers are incredibly precise now, alerting us to everything from excessive emissions and spark plug carbon buildup to loose fuel caps. Last month when my light came on, I first tightened the fuel cap and reset the battery. When the light stayed on, I dutifully went to the 4S shop. The technician's computer diagnosis revealed a minor intake manifold leak - a small issue that can seriously damage the engine if neglected.
