What is the reason why the engine fault light is on when it is cold?

Some car owners will encounter such a strange situation, that is, when the weather is cold, the engine fault light of the car will be on, so what is the reason for the cold engine fault light? 1. Due to the low weather temperature, the fault light caused by the low temperature of the automobile engine is on. If the weather temperature at that time is very low, it is likely that the engine temperature of the car will also decrease, which will be affected when the car is just started, thus causing the engine fault light of the car to light up. After driving for a period of time, the temperature of the engine will reach the normal temperature. At this time, the engine fault light goes out, indicating that the car is normal, so don't worry. It is recommended that the owner warm up the car before driving. The main reason for warming-up is that after the car is parked for a long time, the engine oil flows back to the oil pan at the lower part of the engine, so it is necessary to warm up the car. 2. If the engine fault light still does not go out after the car has been running for a period of time, it means that the car has a fault, which may be caused by carbon deposition in the engine, resulting in unstable internal combustion of the engine. Need to go to the repair shop to clean the engine, gearbox and nozzle.