Attention! Perform work on a cooled engine.
The coolant temperature sensor must be replaced in the following order. Read information from the fault memory of the ECU-KSUD of the "DME" system. Turn off the ignition.
Sensor (2, Fig. 5.194) the coolant temperature sensor is installed on the front pipe of the cooling system. Disconnect the coolant temperature sensor (1) from the sensor and unscrew it. Collect the leaked coolant and dispose of it.
The temperature sensor should be installed in the reverse order, replacing the sensor sealing ring. Return the temperature sensor and tighten it to 13 N·m (1.3 kgf·m).
Check the coolant level and restore it if necessary. Bleed the cooling system. Remove air from the cooling system and check it for leaks.
Read information from the fault memory of the ECU-KSUD of the "DME" system. Check the recorded fault messages and eliminate them. Erase information from the fault memory.
[The text is based on materials from the website BMWman.ru]