Ok so about 1 year ago I replaced the IP, lift pump, APPS (with a Timbo replacement), and placed a FASS inline to ensure fuel pressure. So recently as of last night the truck now decided to trip a 0122, 0123 and a 1693 code. What is the likelyhood the the APPS is bad or what would cause these falts to occur with the truck acting up. Took it to the local shop and had it scanned they got the same codes. They said it's the APPS. So the big question is what is causing the P1693 Generic fault indicating a fault in the bus or PCM/ECM interface. Any thoughts or should I just replace the APPS (again). I just reset the APPS and we will see what happens. Thanks for all the help in advance!