Why does the coolant warning light still illuminate after adding coolant to a BMW?

[Beckett]

BMW added coolant fault light is still on may be the sensor signal line problem. The role of BMW sensors: Monitor the oxygen content in emissions and feed back to the ECU to adjust intake and fuel injection at any time, controlling the air-fuel ratio at the designed theoretical value. Detect the oxygen concentration in the exhaust (before the three-way catalytic converter) so that the computer can determine whether the ratio of intake air to fuel injection is reasonable. Precautions for adding coolant to BMW: When the BMW engine is running at high temperature, do not open the cooling system, otherwise it may cause burns due to coolant spraying out. Only use suitable coolant, otherwise it may damage the engine. After replenishment, please cover the antifreeze cap. The correct coolant level is very important for the trouble-free operation of the cooling system, so the coolant level should be checked regularly.