2007 Volvo S40 Owner's Manual - Page 59

The rain sensor regulates windshield wiper speed according to the amount of water on the windshield. The sensitivity of the rain sensor is adjusted by moving the thumb wheel (C in the illustration on the previous page) up (the wipers will sweep the windshield more frequently) or down (the wipers will sweep the windshield less frequently). On/Off To activate the rain sensor: 1. Switch on the ignition. 2. Put the windshield wiper lever in position 0. 3. Press button B (see the illustration on the previous page). The rain sensor symbol will appear in the lower display. The rain sensor can be deactivated by: Pressing button (B). or Moving the windshield wiper lever down. NOTE The rain sensor function will remain activated if the lever is briefly moved up to activate the "manual sweep" function. CAUTION The rain sensor should be deactivated when washing the car in an automatic car wash, etc. If the rain sensor function is left on, the wipers will start inadvertently in the car wash and could be damaged. The rain sensor is automatically deactivated: When the key is removed from the ignition. Five minutes after the ignition is switched off if the key is left in the ignition. C - Thumb wheel The thumb wheel is used to set the wiper interval when intermittent wiping is selected, or the sensitivity to the amount of rain on the windshield when the rain sensor is selected. Move the wheel upward or downward to increase/decrease wiper speed when the intermittent function is selected, or to increase/decrease the optional rain sensor's sensitivity