Error code 42, no spark

Okay, we're going to skip forward here since you've replaced the fuel pump relay already. There should be 2 hot wires (12 volt) while cranking, where the relay sits. So take it out and check the pins for 2 for 12 v cranking. Now there could be corrosion in fuse panel where the relay is too, so you'll have to check it. If there isn't 2 hot pins at the relay, then go to the back of the ECM and check pin F6, it will be dark green/white. You will have to find it according to color. This wire should be 12v while cranking as well. Here's 2 wiring diagrams to help. Make sure to pay attention to wire condition also, you most likely have a broken or corroded wire. Check around where you have been working on the truck so far, that you didn't move any wires or hide the problem. Since you had the fuel pump running before. Check all the ground wires near the pump on the back of the frame too. The 2 thicker wires at the fuel pump are power and ground, the power is the thick grey wire.

No it shouldn't. Only wire color matters.

Okay, how did you get power to the injectors and can you take a picture of the throttle body with the injectors in it for me? The 2 second prime is a different circuit than the engine running circuit. You can hook a test light to 'battery' positive and check the injector pulse from the ECM while cranking, since the ECM grounds the injectors to pulse them. How long has it been since the engine last ran? Injectors can seize up if it's been sitting for along time. I'm assuming you have fuel pressure now?

Okay, start with verifying fuel pressure, and watch the injectors in the throttle body and watch for fuel while cranking the engine, either the injectors are closed up or the ECM is shutting down the injectors for some reason. Recheck for power at the injectors and make sure there is an injector pulse coming from the ECM. You can use a test light for both these tests. In my previous post are the instructions for testing the injector control. Enjoy the super bowl.