Using AE, I performed the power balance test. Cylinders 2, 3, 5, and 8 all were spiking indicating too much fuel. I then tried to turn each injector on/off. I was able to command injectors 1, 4, 6, and 7 on/off. Injectors 2, 3, 5, and 8 did not respond to the on/off command, all of these are on the same FICM connector. Does this information lean towards a failure in the FICM, failed injector, short to ground, or a PCM/FICM communication error?

Once the truck was started, I was able to clear the injector circuit high and GPCM codes mentioned in my post earlier today.

Thanks.