What causes inaccurate fuel gauge display in BMW cars?

[CadenMarie]

The reason for inaccurate fuel gauge display is usually a problem with the fuel level sensor. Typically, this occurs when the fuel level sensor becomes contaminated and requires timely cleaning. Since gasoline contains many impurities, the fuel level sensor, which is constantly immersed in it, can become polluted over time, directly affecting the accuracy of the reading. Several main factors that affect fuel gauge readings include: 1. Poor quality of the fuel level sensor: The fuel level sensor is essentially a variable resistor. Most current sensors use thick-film printing technology to print resistive materials onto a ceramic substrate. If the resistive material itself is of poor quality (for example, using carbon-based resistive paste instead of metal-based resistive paste), the sensor is particularly susceptible to being affected by the fuel. 2. If there is sticking, or the pivot hole is too small or too large: An irregularly shaped fuel tank can cause mechanical obstruction of the fuel float, leading to inaccurate data from the fuel level sensor. 3. The cleanliness of the fuel itself: When using fuel with high impurity levels, the readings will become unstable.