What is the reason for the engine malfunction yellow light always being on?
2 Answers
Engine malfunction yellow light always being on is because the ECU is alerting that there is a fault in the engine, which is an abnormal phenomenon. The following are the reasons for the engine yellow light being on: 1. Sensor issues. Including water temperature, crankshaft position, air flow, intake temperature, oxygen sensor, etc. When these sensors are damaged, have poor contact, or signal interruption, the car's ECU cannot accurately obtain engine data, which will cause the engine malfunction light to come on. 2. Maintenance issues. Poor engine maintenance is the most common cause of the engine malfunction light coming on. Vehicles have a certain maintenance cycle. If the owner does not perform maintenance on time, coupled with poor driving habits, it will increase the burden on the engine operation, and eventually, it can only be reminded by the yellow light. 3. Oil quality issues. Including fuel and engine oil. The fuel filled in the car generally has a grade, and the engine oil is also divided into semi-synthetic and full synthetic. The manufacturer usually recommends which grade of fuel and which type of engine oil the owner should use. If the owner does not add as required, it will cause engine wear in the long run. 4. Poor combustion of the mixture. Engine spark plug failure, ignition coil failure, fuel pump failure, fuel line blockage, etc. will all cause poor combustion of the engine mixture.
I've got plenty of experience with my car's engine malfunction warning light constantly coming on. The most common cause is a faulty oxygen sensor, which monitors exhaust emissions - the light comes on as soon as there's an issue. Sometimes it's just the fuel cap not being tightened properly, causing abnormal fuel system pressure that makes the light flash continuously. I've dealt with aged spark plugs before - replacing them made the light go off. But you shouldn't ignore a persistent warning light; it could indicate emission system problems or ECU module failure. Driving with it on long-term increases fuel consumption, which is bad for both your wallet and the environment. My advice: get to a repair shop as soon as the light appears to read the trouble codes with diagnostic equipment - this helps accurately identify the issue for faster repairs. Always pay attention to unusual noises or vibrations while driving to address problems early and avoid bigger troubles.
