just took my truck in to have the fuel pump control module programmed. while driving it home from the shop, ding diing, loss of oil pressure. gauge fell to zero and dash read low oil pressure stop engine. after a very quick stop and shutdown. i checked oil. oil full, still fresh as i just changed it about 200 miles ago. started the engine back up and had 35 psi. no knocks or taps.. started down the road again and after about 10 miles, ding ding again. gauge just slowly fell off to zero. again off the road shut down checked everything. all normal. do i have a sensor going bad or is my oil pump relieving pressure? it is a 2012 1500 with the 5.3, and auto trans. any ideas?