LEMON Manuals: Even more car manuals for everyone
Home >> Mercedes Benz >> 1994 >> C220 >> Repair and Diagnosis >> External Pages >> Different car >> Section 71 (Electrical System - Body - 140 Chassis) >> Basic Knowledge >> Rain sensor, location/purpose/design/function - GF82.30-P-4103F >> Rain sensor, function - GF82.30-P-4103-02F

Rain sensor, function - GF82.30-P-4103-02F

WARNING: This page does not describe the selected car, but rather 42 other vehicles, including the 1999 Mercedes-Benz S600, 1999 Mercedes-Benz S500, 1999 Mercedes-Benz S420, 1999 Mercedes-Benz S320, and 1999 Mercedes-Benz CL600. However, it is still accessible from the selected car via links, so may be relevant.

The rain sensor (B38) is connected to the multi-function control module (N10) or the combination relay (N10/2) via a serial data bus. The multi-function control module (N10) or the combination relay (N10/2) transmits a request to the rain sensor (B38) over the data bus. The rain sensor answers each request. The moisture on the window is measured by an optical element operating with infrared light. When the window is dry in the area of the rain sensor (B38) the light is reflected completely. When the windshield is moist in the area of the reflection surface the light is deflected. With increasing moisture the percentage of the light reflected decreases. This light reflection serves as control variable for the interval time. When the rain sensor (B38) recognizes "window moist" the multi-function control module (N10) or the combination relay (N10/2) actuate the wiper motor (M6/1).

Fig 1: Identifying Function Of Rain Sensor
G04636903Courtesy of MERCEDES-BENZ OF NORTH AMERICA.