^^ x2. With that engine, the VCDS is used to look at the dynamic timing, to see where it is, not to alter it. The alteration is made by loosening the 3 bolts that hold the injection pump sprocket to the hub. Essentially the sprocket (and all the rest of the engine) remains still while you put a wrench on the big bolt (nut?) on the center hub and turn it (and the 3 bolts rotate along with it because they thread into the hub). Then tighten the 3 bolts. Viewed as I described it there, rotating the hub clockwise advances the injection timing. (That is, if you have a wrench on the center bolt / nut of the hub, wrench sticking up out of the engine bay, pull the wrench forward to advance the timing.) One note: That is a super sensitive adjustment. Rotating the hub JUST A HAIR makes a big change on the VCDS graph.
Best Regards.... Corsair....
2002 Jetta GLS TDI 5-spd 325Kmi, 2014 JSW TDI 6M
2006 Audi A4 Quattro Avant 2.0T 6M
2004 Jetta GL wagon 2.0L (gas) 5-spd (sold)
[also had 03 TDI GLS 5spd wagon bought new, sorely missed]