181Servic e, Mainten anceDiesel fuel filterOn each engine oil change, ha ve the fuelfilter check ed for any water resid ue bya workshop.Illum ination of A indica tes water in thefuel filter 3.Have fuel filter checked at shorter interv alsif the vehicle is sub jected to ex tremeop erating c onditions such as high humidity(p rim arily in coastal areas), ex tremely hig hor low outside temp eratures andsubstantia lly vary ing daytime and night-tim e temperatures.CoolantThe gly col-based coolant provides excellentcorrosion protection for the heating andcooling systems as well as antifreezeprotection down to ap prox. -28 °C . Itrem ains in the cooling system throughoutthe y ear and need not be changed .Use of certain antifreez es can lead toeng ine damage. We therefore recommendthat you use only approved antifreez es.9 WarningWaste engine oil c annot be disposed ofwith domestic refuse. Observ e the legalrequirements for disposal of old oil andfilters to p rotect the environm ent andyour health.9 Warnin gAntifreeze is a danger to health; it m usttherefore be kept in the original containerand out of the reach of children.