There is a power distribution box under the hood with the relays in it and those power the interior fuse box as well as other systems. Fuse 9 in the interior fuse block powers the diagnostic connector as well as the ASD relay so if the truck runs that fuse is okay. There is also the ground for the DLC in pin 5 if that is bad then you wouldn't have power for the tool either. To test the fuses and the DLC power and grounds a simple test light will work.
Use it first to check all of the fuses with the key on. a fuse can look good but still be bad.
Then use it to test the data link connector. Pins 4 and 5 should be grounds and pin 16 should be power.
Images (Click to enlarge)
Sunday, November 1st, 2020 AT 2:49 AM