faulty water in fuel alarm?

How do you know it is faulty? Do you know for what else it provides warning?

This might be a good place to start. The website itself may be a place to ask more:

http://www.renaultforums.co.uk/17-electronics/93412-laguna-ii-1-9dci-gt-warning-light-water-diesel-filter-odbii-question.html

XXX
February 2017