Rain Sensor: Description and Operation

AIC (Automatic Interval Control)
The automatic interval control (AIC) has the task of controlling the frequency of the wipers in relation to the intensity of the rain and/or the wetness of the windshield. The AIC (rain sensor) is an optical system. The unit transmits infrared light and the reflection of the light back from the windshield is then calculated within the control unit.

In addition to the wiper switch, wiper motor and Body Control Module (BC1) the Automatic Interval Control is made up of the following components:

- AIC optical body (prism)
- Control unit

The AIC optical body, the prism, is firmly stuck to the inner side of the windshield underneath the mirror base attachment and is not a serviceable component; it cannot be removed/refitted in the workshop. Replacement windshields are supplied with the AIC prism already fitted. The prism installation point is selected so that the optics are situated in the wiper's field for both left-hand and right-hand drive vehicles.





The control unit clips to the prism and can be replaced independently from the optical unit. The AIC control unit contains:

- Infrared transmitter and receiver
- Heating measuring optics
- PE (photo electric) cell
- Evaluation electronics