from test manual quote >>

Vehicles equipped with High Intensity Discharge (HID) or LED dipped beam headlamps may be fitted with headlamp washers and a suspension or headlamp self levelling system. Where such systems are fitted, they must work; however, it is accepted that it may not be possible to readily determine the functioning of self levelling systems. In such cases, the benefit of the doubt must be given. Headlamp washers may work in conjunction with the windscreen washers (when the dipped beam headlamps are switched on) or by a separate switch <<


The manual is available on line ! so best to read for your self ans many MOT testers dont bother !