The fault light of the diesel filter is usually due to the need to drain water.

Diesel filter drain:
1. Drain water under the diesel oil-water separator, unscrew the small cap under the filter, and close the oil inlet and outlet ports at both ends;
2. The function of the diesel filter is to filter out harmful impurities and moisture in the fuel system, protect the normal operation of the engine, reduce wear, avoid clogging, and increase the life of the engine;
3. The filter element of the diesel filter mostly uses filter paper, and some are made of felt or polymer materials. The filter element of the gasoline filter mostly uses filter paper, and some use nylon cloth or polymer materials;
4. The structure of the diesel filter is roughly the same as that of the oil filter, with replaceable and spin-on types.

The role of diesel filter:
1. Fuel filter, as the name suggests, is used to filter impurities in automobile fuel, and it is one of the "three filters" we often say. According to different fuels, it can be divided into gasoline filters and diesel filters. They are a kind of wearing parts and need to be cleaned and replaced regularly. Generally, the fuel of a private car is mainly gasoline, so the filter is also a gasoline filter;
2. Generally, the replacement of the fuel filter is carried out when the car is undergoing major maintenance, and it is replaced at the same time as the air filter and the oil filter;
3. But in reality, it can be extended appropriately according to the condition of the car engine. Because the current level of gasoline production technology is relatively high, from production to sales are relatively closed, the gasoline is much cleaner, the fuel filter is clogged and rarely occurs, and it is no problem to travel 56,000 kilometers.