Hey Scooby, welcome to the site, if the dealer swaps out the pump under warranty, see if you can get him to give you the PMD/FSD off of it, couple of us here are trying to do some data collecting on PMD fails, if he won't let you have it, check and see if he will let you take the PMD off.
Under the plastic transistor covers are 2 nut's/studs theory is that they loosen after a while, it would be good to know if those are still tight or have backed off as some have found
Tim, 98GM K1500 6.5TD(L56/L65), Heath PCM,3.73 gear,4L80 tr,4" exh,Amz air filt&dual oil flts, Heath remote FSD, TDO-7 clone turbo, Heath fan clutch,mandrel crossover, pilar gage BST/EGT/TRN, remote elec fan tran cool,alum trn pan