tony:
Both the crank & cam shaft sensors are sending signals to the ECM. The way to ck the coil packs is as follows: Removing 3 of the 4 coil packs at a time. The engine will run on 1 individual coil and eventually smooth out. Repeat this step till you have tested each coil to run the engine. When the engine dies on a specific coil, replace the coil, clear the code and run the truck to check your work. Good Luck and Good Service to you.