The rain sensor will remain active after the ignition is switched off and back on again and will function again if the wiper lever is in position G) and if the vehicle is travelling at speeds higher than approxi-mately 16 km/h (10 mph).
Changes to the functioning of the rain sensor
Possible causes for faults and misinterpretations concerning the sensitive surface 96 of the rain sensor include:
• Damaged wiper blades: a film of water or smears caused by damaged wiper blades can in-crease the time the wipers are switched on, can shorten the length of the intervals between wipes or cause the wipers to run continuously.
• Insects: insects hitting the surface can cause the wipers to be activated.
• Salt deposits: in winter, salt deposits can cause the wipers to continue to wipe the windscreen when it is almost dry.
• Soiling: dry dust, wax, windscreen coatings (lo-tus effect) or detergent deposits (automatic car wash) can cause the rain sensor to become less sensitive and react too slowly or even not at all.
• Crack in the windscreen: when the windscreen is impacted by a stone, a wash cycle is triggered if the rain sensor is on. The rain sensor will then reg-
ister the reduction in sensitivity of the surface and adjust accordingly. The size of the crack could af-fect the way in which the sensor activates the wip-ers.
A WARNING
The rain sensor will not always detect every rain shower and activate the wipers.
• If necessary, switch on the wipers manual-ly if the water on the windscreen restricts the field of vision.
m At regular intervals, clean the sensitive sur-L!...J face of the rain sensor and check the wiper blades for damage 96 (arrow).
m We recommend that you use an alcohoi-W based glass cleaner to remove wax and pol-ish.
Checking and refilling the windscreen washer fluid level
Fig. 97 In the engine compartment: cap of washer fluid reservoir.
r--T'n First read and observe the introductory L-J,:,JJ information and safety warnings & on page 116.
The windscreen washer fluid level should be checked regularly and topped up as necessary.
120 I Before the journey
A filter can be found in the feed throat of the wash-er fluid reservoir. The filter keeps large dirt particles away from the washer jets when refilling. The filter should only be removed for cleaning. if the filter is damaged or cannot be found when refilling, these dirt particles will reach the system and will block the washer jets.
• Open the bonnet & 350.
• The washer fluid reservoir is identified by the $ symbol on the cap 97.
• Check whether there is enough windscreen washer fluid in the reservoir.
• To top up, mix clean water (not distilled water) with a washer fluid recommended by Volkswagen Commercial Vehicles Observe the dilution in-structions on the packaging.
• At low temperatures, add a special anti-freeze agent so that the fluid cannot freeze &.
