INTENSIVE CLEANING WIPER SWITCH from 03/1999 on BMW Parts# 61318375407
When the rain sensors detect rain or road spray this function will automatically wash the windshield (and headlamps if you have headlamp washers) in conjuction with the wiper blades being automatically activated by the rain sensor.
US Spec E46 never came with the S stalk for automatic washing. Only E53 X5s, E83 X3s and E39 M5s in the USA are the only cars with the S stalk. The European BMWs with the S stalk use the stalk to access a secondary power washer tank with concentrated fluid. In my car I simply wired the stalk to my rain sensor module to wash the windows after every 5 auto swipes. All US spec 2001 to 3/2003 E46 cars with rain sensor/auto head lamps should be prewired for pin 10 to accept the S stalk. After 2003 the wiring for the rain sensor and auto headlamp functions changes dramatically in the E46 cars. BMW switched to a ribbon based wiring for all in car accessory functions after 3/2003. So I cannot speak on those cars.