What are the reasons for the engine fault light being on without starting?

2 Answers
DelAbigail
07/28/25 5:24pm
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.
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LaRosalie
08/11/25 11:40pm
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.
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