how can i fix my vw tdi caddy van y reg?

i have a tdi caddyvan 1.9 it has over 100,000miles i am the only owner this van has never missed a beta and its well serviced i have left it reversed in my drive way on a slight dip but i thought the battery was dead so i jumped it but it is just turning ober but on the dash the glowplug icon does not flash up do you think its electrics or the glowplugs that need replaced? thank you stevie