What are the reasons for the engine fault light being on without starting?
3 Answers
The reasons for the engine fault light being on without starting are: 1. Vehicle self-check; 2. Incomplete combustion in the cylinder; 3. Increased carbon deposits in the intake tract and piston top; 4. Spark plug failure; 5. Ignition coil failure; 6. Faulty sensors or computer board itself. The car engine is the device that provides power to the vehicle, serving as the heart of the car, determining its power, fuel efficiency, stability, and environmental performance. Car engine maintenance methods include: 1. Regularly changing the engine oil and oil filter; 2. Maintaining good crankcase ventilation; 3. Regularly cleaning the crankcase; 4. Periodically cleaning the fuel system; 5. Routine maintenance of the radiator.
I've encountered the issue of warning lights appearing before starting the car several times. Generally speaking, this is a normal phenomenon during the vehicle's self-check process. As long as the lights turn off after turning the key, there's no problem. However, if the lights remain on after starting, the causes can be more complex. Common reasons include unstable battery voltage or loose wiring causing false system alerts; or sensors accumulating dust—for instance, a dirty oxygen sensor might send incorrect signals. Older car models are more prone to such issues. It's advisable to first check the battery connections and clean the sensors. If the problem persists, it's necessary to visit a repair shop to check the fault codes. Don't delay addressing it to prevent minor issues from escalating into major problems.
As an enthusiast who often helps friends with car repairs, I've noticed that lights turning on without the engine starting usually indicate a weak battery or poor wiring contact. Last time, my neighbor's car had this issue, and it turned out to be loose battery terminals—tightening them fixed the problem. It could also be a blown fuse, especially in older cars where fuses tend to degrade. I recommend checking the dashboard first to see if other lights are also on. If only the warning light is illuminated, it might just be the system performing a self-check. If the light stays on after starting the engine, inspect it immediately—don't ignore these small signals.
