Diagnosis instructions

Initialization of the rain sensor 

To ensure that the optical measuring procedure for the detection of precipitation functions properly, the rain sensor must be adapted to the windscreen.

A prerequisite  for trouble-free initialization is that the windscreen glass is dry, clean and free of defects in the area of the rain sensor.

The initialization is performed using the "Initialize rain sensor" service function in the BMW diagnosis system. This service function deletes the adaptation values in the rain sensor.

Special feature:  Initialization is only carried out after a terminal change. As the rain/light sensor is supplied via terminal 30g by the junction box, there are the following possibilities to carry out the initialization:

• Allow the vehicle to go to sleep
• Briefly remove the fuse for terminal 30g in the junction box

After a 10-second waiting period, the new adaptation values are determined automatically and stored by the sensor. A re-initialization of the rain sensor is required:

• After replacing the windscreen
• After installation of a rain/light sensor